You have some great answers below, so let me just add a few small considerations.
In order to make money in real estate you need to be able to find people who need to buy or sell. We have a term called "lead generation", and in order to be successful you need to be very good at generating leads so you have people to talk with about buying and selling.
Then once you talk with them you need to be able to determine how serious they are about buying or selling. Part of that process, especially for sellers, is effectively negotiating price, terms, and commission. A properly priced listing will sell more quickly, sell for a higher price, and make for a happier seller.
Just-released statistics show that Keller Williams Realty is a leader in a couple of key components that will help you achieve success in these activities:
1. KW agents worked with more buyers and sellers in transactions (we call them "sides", as is side of a transactions) than the National Association of Realtors average.
2. KW agents earned more commission as a percent of the sale than the National Association of Realtor averages
3. When the average percent of Realtors declined across the board 3%, Keller Williams agent growth was 4%, or a net gain of 7% more agents.
I would be happy to arrange for you to speak with some successful agents in our office so you can ask them about the training available that lead to their success.
Good luck to you! Two great books to read, "The Millionaire Real Estate Agent" by Dave Jenks, Jay Papasan, and Gary Keller, and by the same authors, "SHIFT".