The big danger, of course, is having such a fantastic time looking up all the details, working them into your story and so on, that you lose focus on what you are meant to be writing in the first place! What I've found useful here is to write down a list focussing on the main things only. Naturally I then get my first draft down and then begins the lovely editing process! There is always something to be cut out!
So feed your imagination by reading widely and then be selective what you draw on to create your characters and fictional worls.