I have mentioned a few times the website http://math.stackexchange.com/ and suggested that you take a look at it and use it as a resource. I believe it is a really useful site when used appropriately. Some of you have asked for additional references, and I think this site may help supply some of them.
Here is a short list of questions posted on the site that may give you an idea of its value:
- Proof by strong induction.
- Proof by induction for inequality.
- Proving a theorem in classical propositional logic.
- Understanding proof by contradiction.