Quick Reference: Google Advanced Operators (Cheat Sheet)
Awesome reference for how to find exactly what you want with Google and the proper syntax to do it. A better layout than googles help pages. Claims to have used their permission; which is interesting, if true.
Nice to have this put together. This is the most complete sheet I have seen yet. This left out my very very favorite, the ‘index of /(topic)’ search, which I use for everything from MP3s to clip art.