I got a very abrupt and in-depth education in map projection today and discovered a couple invaluable resources that I thought I'd share.

1. Map Projection - Wikipedia (obvious, but gives a good overview)
2. How to choose a Projection - Hunter College of the City University of New York - Dept. of Geography (invaluable in explaining the basics of map projection and what to consider when deciding what projection to use)

Hope that helps some of the other beginner mappers out there like myself. Enjoy!