I've read posts before where members have talked about basic functions and features of the game that they did not discover until many hours into Skyrim. Many people have said that they didn't know you could rotate the characters and items on the loading screens, others talked about not being aware that you can pick up items and move them around (a feature that's been in since Morrowind if I remember correctly).
I'm wondering, what other features did you guys (and gals) not discover until you had logged many hours in the game. Perhaps this thread will also be helpful in allowing others to discover new features.