Amazon provides a fairly complete listing of books in-print and offers helpful reviews by professionals and customers. Their business is selling books, so don't expect them to tell you if we have the book in our library!
Use the Amazon.com - Advanced Search feature.
Google Books is a full-text searchable database with millions of scanned books from libraries or directly from publishers. The strength of Google Books is that you can search the majority of the books from cover to cover and find books in which a chapter deals with your subject.
Online library catalog that lets you look up books, dissertations, microform, journals and multimedia items in other libraries.