Best Online Broker?

[Scruffey]

So, I know a pretty decent amount about investing and playing the stock market but I am pretty young and haven't started yet. I know a decent amount, except where to start. I am looking for a trusted online broker that is optimal for young investors who are interested in risking fairly small amounts. I am hoping to find one with low commissions and hopefully no monthly fees. There seems to be a few good ones that I have found (sharebuilder, tdameritrade, etc) but I was looking for some feedback on the best one for young investors.

Also, I am not sure if it is optimal to use the online investing options through the bank in which you have a checking account?? (chase, wellsfargo, etc.) Any feedback would be great.