since once in a while all of us encounter an ongoing discussion about historical events or we are being asked if know more about xyz it can't harm to know what history and what isn't.
History isn't just a factual science, but it's always also being used or better abused to make a point, to tell a very subjective story. The abuse of history is perhaps best to compared with the situation of a couple who just split up and who are intending to get divorced (even worse when they have children and both want to engage in a custody battle)
Both sides want you the third person to hear their story of how the other side has done this and that and overall is as guilty as hell for the situation finally ending in a divorce. Very often both parties involved in this struggle want you, the outsider, to hear their story, to take their side, to make sure that only they get your sympathy. It's human and it happens many times in our social life where we are getting drawn into decision making who is 'completely' right or 'totally' wrong. It's not often grey, but usually:black or white.
History is very often describing situations where whole nations are in such a battle for getting you, the outsider, the observer, the researcher or the just curious person on their side. Be always aware of that and do your research before getting getting involved emotionally and take a side, see it either black or white as desired by all parties. Another parallel between private life and history is that in your private life those who shout loudest are often the ones who are wrong and in history those who kill people are of course wrong, but also eager to get your sympathy because not they are guilty, but the other side, so they want you to believe. And be aware that as with couple where the woman says the man hit her where you can see they obvious marks on her face, what you can't see as obvious evidence are the numerous provocations before. Before hell breaks loose:there are also of course many many situations where men hit their women completely unprovoked, because they are drunk, bad mannered or because this or that, as well as there are also violent women.
After this warning what history unfortunately often in reality is: a giant 'blame game', here's what you can do to prevent being dragged into a quagmire. Be aware of the fact that more facts you learn the more the manipulators will hate you for that. Be also aware of the fact that many of the most evil players try to destroy evidence of their deeds and try to cover it up or even blame it on others as eg the Soviets did quite successfully for many years with the Katyn massacre.
Always search for the 'bodies' and do your research as a detective would do to uncover murder and find the right perpetrator. It often helps to know the circumstances, the context of the murder. The situation the killer is in and was 'forced' to kill his victim. Such often circumstantial evidence should also be considered when it comes to history where perhaps the crime itself is covered up, but not the fact that eg 20.000 bullets are suddenly missing from stockpile 24 (just made that one up).
Try not to concentration too much on the 'action' a war, an armed conflict, but look what happened before, what led to the outbreak of the war. When wars start the outcome is very often uncertain, since both/all sides are convinced to be victorious otherwise they would be just plain stupid to getting involved in it, wouldn't they? Once it started it comes to know the battles which are just like to punch in the face very obvious signs of conflict whereas the 'insults' happened before the outbreak of the war are often overlooked because they are less obvious and 'emotionally important' only to one side, who knows all about the importance of 'little things' and you the outsider don't.
Try to see history as a timeline of events which are a web and which are all connected in one way or another. A system of myriad of roads that lead to a long period of peace or a seemingly never ending chain of wars. Often the direction where history is leading peoples is dominated by personal ambitions, wisdom or stupidity of individuals such as emperors, politicians or even business people such as Cecil Rhodes who determined the fate of whole countries or even founded them where before there were tribal territories. Always try not only to listen to those who finally 'made it', like Rhodes in Southern Africa, but also to those who finally lost the freedom, their small kingdom and whose history is written down in languages we don't speak/understand. We don't have to look to Africa when it comes to the history of the subdued people and the need to know all the stories albeit if they are written down in languages we don't understand. Just imagine the couple in the divorce battle where one speaks only French, the other only English. You don't speak French like the husband also does, so you won't be able to listen to her side of the story, because you don't understand what she tries to tell you.
We now fortunately live in the Internet age where much more information is getting available to the public then previously when knowledge was only in available in books which were either stored in a library perhaps too far away for you or you were forced to buy often expensive books you probably couldn't afford to buy. In the Internet age we are lucky to have Wikipedia, but the words of caution also apply to this otherwise fabulous new source of knowledge. Be ware of that the fact that
a.) Wikipedia is maintained also sometimes 'ill spirited' humans who want you only to read their side of the story
b.) Wikipedia is almost never 'complete', which means delivers as much,often crucial info, than books, documentaries, documents, audio & video recordings can.
c.) If you know more than one language compare the different language versions of one Wiki entry. Often the quantity and quality of the article in another language is astonishing.
On the other hand hyperlinks are often found in Wikipedia which lead you easily to other sidelines of 'a story', a page of history.
Google and other search engines are also useful , but also be aware that a lot a bullshit can be found on the internet and a search engine won't warn you:this is BS ! So you have to be careful what sources you can trust. Always look for the original sources from the history period you are studying, since also authors of books are often manipulative in one way or another, often unwittingly by omissions because they either didn't know the factoid or deemed it too unimportant for you to read it. Also be aware that those historic recordings may be incomplete,slightly or completely wrong because those people of time wanted to create a certain image of themselves or perhaps later other people altered the recordings. Mankind seemed always keen to be as subjective as possible and that has changed ever since.Especially when it comes to ideologies where they are obsessed with getting you, the outsider ,the independent thinker on their side. Ideologies fear facts, because they might result in doubts that this believe the are upholding is either slightly or completely. The more 'completely' wrong it is the more brutal the suppression of the facts, the truth, you can bet on it !
So history isn't easy, but the digital age makes it easier to get closer to historical facts, if you are always aware that even Google can't find all the things powerful people don't want you to find or even more tricky:they might insert forgeries into 'the Google'. Forgeries such the The Protocols of the Elders of Zion are often used to reinforce believes you are already holding. We humans tend to believe things very easy when we want them to be true, when a story sounds 'sexy' instead of boring, or when nice looking pictures or graphics are added which in itself are based on wrong data or when a text is added to picture which gives it a completely different meaning. It's never wrong to be a bit skeptical, always try to find the original source and then start your interpretation, don't rely on others to that for you. Those other 'interpreters' may not know all facts or may come to conclusions that match their personal believes, serves their ideology. Some historians also didn't completely comprehend the possibilities the digital age has to offer in researching historic records, or they see it as a threat to their position as 'editor' of history, because so far they could decide what historical records made into their books or which specific info from those records they did us and which other they omitted. You can spin pretty much especially with omitting info and sometimes small things which might have been overlooked by the one historian writing book 'A' could be very useful to the author of book 'B', because he has knowledge of a different context. That's why it's so useful to have more and more of those records scanned and opened to the wider public.It diminishes or at least limits the role of the former 'keepers of wisdom' or 'messianic' historians. Always look up biography and bibliography of an author and try to find out whether he/she is factual,neutral or biased. If the latter it's also OK to read,but everything has then to be put in a context.
As it happens most nations are trying to sell you an overly optimistic picture of their nation's past, the opposite is true with the Germans. Their historians tend to be overly focused on Nazi evil and on negative views of the Kaiserreich and especially their last emperor: Wilhelm II
History never repeats itself as it is claimed so often, because it's a very complex network of events which are influencing the path of history like gravity and other forces influences all objects in space which also interact constantly. Individuals may make the same or similar mistakes as other individuals before them, but the constellation of actors and/or circumstances is never exactly the same.
Although it's always good when 'new' historians publish books with additional information on e.g. The Great War, the public tends too often to hype it or to view either the book or/and the author as the new 'bible/messiah'. Especially when a country formerly overladen with PC soaked history is welcoming books from Australian authors.
The fact that a new book on the events of the World War I arrived in the book stores doesn't mean that the author is completely right about everything. As it was premature for scientists who knew a lot, but not all, about physics to insist in the early 1930s that the atom can't be split, it is premature to state in a book's foreword that "unfortunately it's impossible to read all available archived material of a certain time period". Of course it's difficult for one person to be familiar with all languages significant documents in various archives are written in, but that doesn't mean it's impossible.
a.) There are some expert historians who do actually speak 10+ languages
b.) OCR and other means of transcription offer the chance to use automatic translation. Not yet perfect, but a very promising technology
As mentioned above the 'bias' of a book about history can sometimes tell what languages the author knows and where consequently the research was done and where it wasn't.