MIT Mathematics for Computer Science (harder but still not that hard):
Steve Skienna discrete mathematics course (graduate course based on Knuth's "Concrete Mathematics", quite hard):
I also recommend checking out some books:
http://infolab.stanford.edu/~ullman/focs.html - free "Foundations of Computer Science" book that combines discrete mathematics with C programming and some theory of computation stuff, a pretty good way to make things more practical
http://www.amazon.com/Discrete-Mathematics-Elementary-Beyond... - very pleasant introductory discrete mathematics book, a welcome break from the usual "brick" format and covers some important topics that often do not make it into the normal discrete mathematics curriculum e.g. induction on trees.
http://www.amazon.com/Introductory-Combinatorics-Modern-Birk... - classic introduction to combinatorics
Get dozens of book recommendations delivered straight to your inbox every Thursday.