Visit investopedia.com and read a few articles. Estabish goals for yourself. How much money would you like to make? How much time do you want it to take you to make that money? Find one or two blue chip stocks, research them and decide when you think is the best time to buy. Find an online broker system like scottrade.com or etrade.com. also yahoo finance and google finance both are great resources.

Go to Vanguard or Fidelity (among many others) open an account and buy something. If you are old enough and rich enough, no big deal.