I'm not sure if this necessarily answers your question, but one piece of information I wish I knew earlier in life is that it's good to have credit cards (if used wisely).
I've always been budget-conscious, and I was a Finance major in college, but as recently as last year I still didn't know that having open credit cards is beneficial to your credit. A year ago I got a free copy of my credit report, and noticed that I had three open credit card accounts that I didn't use. A discover card (don't remember applying), a Circuit City card (found a better deal on that bigscreen tv at costco), and a BOA credit card with my college on it (free t-shirt!). I called up all three companies and had the cards cancelled, thinking that it was the right thing to do. In a matter of 20 minutes, I lost $20K in available credit! I had also cancelled a Mets credit card that was open in '99, while I was a sophomore in college. Currently, my longest active credit card is from '03....I wish I still had that '99 card active!
I hear people mention how bad the scams are on campuses (sign up for a CC, get a free frisbee!!!), and they tell people not to fall into the trap. I've learned lately that it would be wise to get that free frisbee though, so that you can establish credit at 18 instead of 22. (of course, this assumes that people use it wisely....and that's the big issue).