One of best book I've seen was by Jiri Dostal (1993). It is very rigorous and is not for the casual reader. But it has very clear explanations. The book is very expensive though (see amazon). Its best that you borrow a copy from your school's library before you invest.
Walt Jung (2004) is also good for applications. You can also use Horowitz and Hill (1989) which has some good material on op-amps.