Alright, people, I'm working on a fic, and for purposes of plot and structure, I am in need of some information. This isn't something I can just look up in the appropriate book, either; I need the expertise of those who have spent their time putting together clues from the various books.
I need a map or coherent description of the layout of Hogwarts Castle. What leads to where, where the entries to the dormitories are, what passages lead where and how to get to them, and so on.
Is there anything like this in existence? I plan to check the Lexicon, but I don't know where else I might look.
Any ideas, thoughts, lists, or links are heartily welcome.