I agree with Tib on the For Dummies series - get Personal Finances for Dummies, as it covers a lot more ground for someone that is young and has not had to manage their own finances before. The book is a gold mine of information.
There are personal finance websites, my suggestion for starting out would be to follow the Motley Fool.
http://www.fool.com/
Remember to take all advice with a grain of salt and a healthy dose of skepticism unless you are confident in the impartiality of the source of the information. Stock brokers are salesmen. For an interesting read on the life of a junior broker at Solomon Brothers, get Liars Poker by Michael Lewis.
I would steer clear of individual stocks for the time being. Mutual funds that are tied to stock indicies generally have very low maintainance fees, and are frequently no-load funds.
Personal Finance for Dummies explains all of this in detail.
I wish I started investing when I was your age. 6 or 7 years can make a huge difference.