There's no such thing as too much knowledge. Read as much as you can, but don't take any single book/theory as the 'right' theory.
Realize that most books out there are very general, and realize that you should take their advice with a grain of salt and adjust it to your level of play. No two situations in poker are the same, and so there is no 'right' way to play, say, AA. You might limp-raise vs an aggro player, you might open push all in vs a calling station, you might raise a standard 3-4BBs etc etc...
I'm rambling too, but my point is that reading never did any harm - as long as you don't take what you read and accept it as the only way to play. Mix and match your own style from all the information you gather from books, articles and forums.