I'm looking for course notes and assignments and hopefully some example exams for Discrete Math, I'm taking a placement exam in the subject after having taken it 4 years ago.
This is the discrete math course one in my school. It contain lecture notes, homework and previous exams. http://www.cs.sunysb.edu/~cse547/
When wanting to know about a particular mathematics subject, I often find that starting with the "further reading" section of the relevant wikipedia page is a good way in.
if you don't mind shell out a good amount of money, Concrete Mathematics by Graham, Knuth and Patashnik could be nice (I own the first edition)
When it comes to textbooks, the Kenneth Rosen text Discrete Mathematics and its Applications is highly recommended. I was first introduced to it at my university, but I've seen it cited in several places.
For quick review Schaum's Discrete Mathematics is good.
If you have time, read Foundations of Computer Science By Aho-Ullman. It's free and available online. Around 800 pages.