Here are some links for around the interweb that are relevant to fuzzing or security testing in general:

Wikipedia on fuzzing (http://en.wikipedia.org/wiki/Fuzz_testing)

A good list of fuzzers (http://www.infosecinstitute.com/blog/2005/12/fuzzers-ultimate-list.html)

Another good list of fuzzers (http://www.fuzzing.org/fuzzing-software)

For tools and information on security, check out http://www.hackerscenter.com

If you write software, you need to know about the Security Development Lifecycle (SDL) and Microsoft's is as good as any (http://www.microsoft.com/sdl), or get help here.