I just got out of college a year ago and I can tell you some things I suggest.
1. Don't get an unsecured credit card(certainly not more than one). Do get a secured one for credit building.
2. Invest. Right now the market is cheap and this is the time to buy. If it goes down more keep buying. Or even better get a pro to help you set everything up.
3. Also when you start buying stuff for real. Set aside the cost of the warranty in a seperate bank account. By doing this you will build your own insurance for things.
4. Try to buy a house ASAP. The market is very good for home buying. You will need to establish credit for this. Credit requires extreme discipline.
I suggest you spend this evenign setting up a budget.
http://www.daveramsey.com/the_truth_about/budgeting_3457.html.cfm
check out the site above for advice. This guy knows his stuff.