Normally the commission is paid by the seller of the property. Many brokers do charge buyer's a fee usually called a transaction/processing fee. These amounts can range as high as $750.
If you are planning to buy in Florida, ask the agent what fee is charged by their company, as it can vary widely from company to company.
If one is a buyer, then the fee is nothing or something depending on what you need as buyer. Normally, in a MLS situation, the buyers agent is given a cut of the selling agents fee, and the buyer will pay nothing to little to have an agent help them - but again its a issue you will work out with the agent.