just a general question, but what are you composing?
I am sure there are some good books on general composition - but different types of photography call for differnet compositions - further and more importantly - aquireing those different compositions requires different skills in different situations
Another (cheap) tip is to go the art galleries and photo exhibitions and look at the work of the best people in the areas you are interested in and take note of how they compose their photos
I'm not all that specialized. I've been photographing people, landscapes, still lifes and anything else that grabs me. Maybe there's nothing that general.
I think you're right about observing the work of the best and I've been trying to do that with books.