They are all pretty much the same, you log in to the web interface and start buying and selling. Scott, sogo, schwab, etrade, fidelity, tradeking, IB..the list goes on. I'm using sogo right now because they have a nice non-flashy easy on the eyes interface and more importantly because they only charge $3 per trade while the other's charge fees of from $7 to $12 per trade.
https://www.sogotrade.com/Setup/Default.…
And one last word of warning, never never buy and sell the same stock in the same day more than three times a week. It's the PDT rule.
While you are learning about stocks also read up on options. That is a must if you want to be an investor. Take a look at LEAPS, you will be glad you did.
I use both BoA and E-Trade,,
ETrade is reasonable depending on how many trades you make in a quarter, although I only have my IRA's with them,
Bank of America has no fee trading if you have a qualifying checking account, I like E-Trade over BoA's brokerage set-up, I have a cash account and IRA's with BoA,
TD-Ameritrade is also a popular online broker, I've never used them,
For me, Etrade is the best site. The customer service is awesome. Here is a blog that talks about using them. Hope it helps you:
http://www.makingmoneyinvesting.blogspot.com/
I use interactive brokers. Their trades are low.
Below is a guide for selecting a broker.