The best book on play if you can find it is Goren on Play and Defense. Goren advocates a clear way of thinking about play that is unequalled by any other writer. Learn everything in it, then go out and play. When you feel that you have misplayed or misdefended, go back to the book and compare what you did with the book's general recommendations. After that, get All Fifty-Two Cards by Marshall Miles. There is no book available that teaches how to think about bidding, and the range of opinion is so wide that you can't really learn much by asking other players. Whatever bidding system you play should handle all the common situations well. I would recommend strongly that you stay away from systems that lean heavily on preemption such as Bergen until you have mastered all the common constructive situations. For example, exactly what does a standard single raise encompass? What strength range? Which distributions? When you can answer that kind of question about every common bidding sequence and acquire a level of easy competence, you will be well on your way.