Not all agents work the same way. The most important attribute of an agent is that he/she is well connected to the real estate industry. He/she should know the market and provide information on past sales, current listings, his or her marketing plan, and at least 4 solid references. In addition, you also want to look for an agent that is honest, assertive, and one that best understands your needs.
Try to go with a local agent. They can better serve your needs; they are familiar with what the local market condition is, the local prices are, and what's hot or not in your community.