Every link on this page has contributed towards my own growth, and so I only include the following resources. I believe each will truly help you learn to succeed in the stock market.
TradeKing: $4.95 trades, no account minimum Open an account at TradeKing
SureTrader: For non-U.S. residents, $4.95 trades Open an Account at SureTrader
I ranked my favorite books from this list in my 8 Top Investing Books post.