A military saying "If you have to go through a mine field, at least follow someone who knows the way" is somewhat apropos of the home selling experience. Dealing with federal and state laws, brokers, mortgage lenders, and prospective buyers can be daunting and a good reason to find a good listing agent to represent you in selling your home.
The following are a few questions to help you interview references given to you by potential listing agents to help you narrow your search to the best agent for your circumstances.
Where you satisfied with your listing agent?
Most people will say "yes" regardless of how they felt. Follow the question up with "What did they do that you found was the most helpful?" This should give you a better idea if they can quickly respond.
Did they get you all official documents in a timely fashion?
It is better to have an agent who knows that on a financial transaction as big as a house sale, sellers want time to review legal documents so they can get any questions answered and possibly have their lawyer review them.
Would you use the agent again?
This question does not demand an expose of good or bad behavior or actions, but a fairly safe "yes" or "no". If there is any hesitancy, you can follow up with "Was there anything you would have liked them to do differently or did not meet your expectations?" This does not peg the agent as bad in anything they did, as a "What did you not like?" type question may suggest, just that the agent's style did not necessarily mesh with the client's expectations.
Did you get your questions answered to your liking in the process?
Let's face it, unless you are a property investor, you do not have a lot of practice and experience selling homes. Having the safety of asking your agent questions and getting enlightening answers helps you go through the transaction in a knowledgeable way (don't settle for the "just trust me attitude").
Did you feel like your agent was representing you or the buyer?
Don't leave money on the table, even in tight economic times.