You can search the scanned copies of books within Google's Book Search. In many cases, you can even view some pages within the books.
The University Libraries subscribes to a number of online collections of mathematics books. This list gives you an idea of what we have available for you. If there is something that you are looking for that is not here, please contact me.
Note: Springer books list books ordered by date, newest to oldest. The books at the top of the list may not be available yet because they are so new. Scroll down to find the books that are fully published and available.