Normally one opens a brokerage account puts in cash which is used to purchase shares of companies (equities), ETFs, or mutual funds. Often, it's a discount brokerage to which you deposit cash and you submit buy and sell orders online.

There's a Discount Brokers discussion board where you can talk to other Fools about discount brokers. Personally, I use Scottrade, which offers $7 equity trades and no account minimums or maintenance fees. If you are interested, I can give you a referral which will give you a couple free trades to get you started.

Fuskie
Who wishes you luck getting started with investing...