1. The first advice I will give you is to clear your mind of what you think you know. So much false information has come out about the Titanic, you need to clear your mind of all the false information so that you can replace it with true facts.
2. Rely on primary source documents. There is nothing like learning from those who were there about what happened. A lot of survivors gave detailed accounts of the sinking. Many accounts have been available to the public for years. Others have recently come to light. Still others have yet to be discovered. The word of a witness trumps the word of an armchair historian who sits around, speculating about what might have happened. Now, there are several things you need to keep in the back of your mind as you go through the survivors' accounts.
a. Some survivors lied. For example, 2nd Officer Lightoller lied about some of the things in his testimony that might look bad for the White Star Line. Others lied to protect their own reputations.
b. Compare what survivors said about certain events. Some will contradict each other and it is important to keep those contradictions in mind.
c. As time went on, the survivors' memories got mixed up and replaced things they forgot with things that didn't happen. This happened with several including Eva Hart. Be especially cautious about the later accounts. Compare them with the accounts given right after the disaster by the same people if you can.
d. With secondary sources, don't discredit all of them but be careful. Newspapers tended to add details to make the accounts more harrowing and sell more newspapers.
3. Look at the common practices and policies of that time before you condemn the actions of those in history. There were some practices and policies that would horrify us today who are more safety conscious. For instance, many ships didn't have enough lifeboats. Not just the Titanic. Another example is that it was common at that time for captains to speed up when icebergs were nearby.
4. Don't trust other professing Titanic historians at face value. Do the research and check the facts when you read what "researchers and historians" are saying. Even Walter Lord, the ultimate Titanic historian, made mistakes in A Night To Remember, though his information was correct for the time.
5. Whenever you read a book, check out the sources of information in the back. If there aren't any, be even more suspicious about what you read in the book.