I knew pretty much nothing - literally - other than I was blindly investing in my company's 401k a few years ago.
I now feel 100% confident to even advise other people how to invest and handle my mom's accounts.
All it takes is a little bit of time and research. Knowledge truly is power.
http://jlcollinsnh.com/stock-series/^adding this link as it is definitely one of the best out there in terms of how the whole thing works and what stuff you need to figure out.
Read the Boglehead links, Jim Collins, post questions around here, and in a very short time you'll feel comfortable to take over your own finances and investments.
And I agree with the others: Vanguard is best, but you can do just fine with Fido (they have similar index funds in their Spartan series, just stay away from "managed" funds and you will pay pretty much the same low expense ratios as with Vanguard). Run far away from Edward Jones.