Two questions for you:
1. HOW MUCH money are you investing?
2. WHEN do you need the money?
If you are looking for a quick buck or don't have much to start off with (less than $1000), you're better off throwing your cash in a high yield savings acct or money market.
If you have a decent chunk of change burning a hole in your pocket or plan on investing for a long time, you will make the most money if you BUY and HOLD. We're young enough to dump money in and weather the storms of the market. Instead of picking stocks (which is very difficult and time consuming), consider some index funds. There are little to no fees involved in maintaining them (as opposed to mutual funds) and the return is a lot higher.
I also used Scottrade in the past, but have switched to Zecco for its low cost trading.
If you want to learn more, read up on
www.investopedia.com, there are some good articles for newbies.