Weight Training Guidance

veggie

I am fairly new to weight training - started with some dumbbells at home last December -- and have just joined a gym. I am totally confused as to the best approach to gaining muscle. The trainer at the gym is recommending a full body (1 set of 15 reps per exercise, with 2 exercises per body part) 5 days a week. This seems like over-training to me but I don't know that I know enough to be sure! She also recommends a lot of isolation exercises.

What I am really after is a book that can provide me with some sound routines I can follow. My weight is fine, I am just looking to gain strength and mass (I realize that I am not going to be able to gain unsightly amounts of mass :-) ). But I am totally confused as to the best approach for doing so.