Vanguard funds
I've been with Vanguard since day one of my AF career. Well, the first chance I got to call them without the MTIs around...I can't sing their praises enough. Excellent customer service, no - load funds plenty, and solid performance.
I have their S&P 500, 2045 retirement fund (Roth IRA). I also invest 10% base pay (current max allowed) into the USAFs TSP program.
Key is to start early in investing and stick with the basics...I recommend Personal Finance for Dummies as a starting point for anyone out there interested in educating themselves...It will provide you with a solid foundation...
Other have recommended some excellent books as well...
Bottom line: educate yourself on the basics and start early and invest consistently...
V/r,
Cajuns fan