I do trade a little. If you have a 401k plan, you are a trader, you just might not know it.
I usually stick with well known companies that I know enough about. In my opinion, it is a great time to buy for long term. Stocks are still down, and they will go back up once the economy rebounds. Gas companies are companies I have made a lot of money from in the last few years.
Don't go in expecting to make some quick cash. Invest in companies you know something about. I usually set a certain price that I would sell the stock, this way I make money because the market can get harsh at times, like these last few months.