Searching vulnerabilities and exploits

vendor websites

every vendor interested in security has review page about last critical vulnerabilities

public known

http://www.milw0rm.com
http://www.exploit-db.com
http://www.packetstormsecurity.org

google searching

google books - chapter "Google Hacking for Penetration Testers, Volume 2: Chapter 6 - Locating Exploits and Finding Targets"
google operators filetype:.c + exploit

decoding exploits (and fake identification)

shellcode2asci.zip (python script for revealing fakes)
http://pyms86.appspot.com (x86 instuction translation)