Books
This is an incomplete list. If you use any of these books to help you solve homework problems, don't forget to cite them, just like you would any other source.
Algorithms: A Creative Approach:: Udi Manber
Introduction to Algorithms:: Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford Stein
The Design and Analysis of Computer Algorithms:: Alfred Aho, Jeffrey Ullman, and John Hopcroft
The Algorithm Design Manual:: Steven Skiena, 1997
Algorithms:: Sanjoy Dasgupta, Christos H. Papadimitriou, Umesh Virkumar Vazirani
Algorithm Design:: Jon Kleinberg, Eva Tardos