My answer is very similar to Susan's.
I would become informed as much as possible about the process. There are many good sites to do so, but Trulia is the Best because I'm here.... ; )
Then if you choose to use a full-service Agent or a Flat Fee service I would interview Agents to find one you feel comfortable with.
I say Agent because not all Good Agents are members of NAR and not all the members of NAR are good Agents.
I would also read the Blogs Rockinblu provided links for as they are informative and well written IMO.
The main point though is you are going to be involved in a process that can impact you financially so if you are not willing to take the time necessary to inform yourself and inform yourself and inform yourself. GET AN AGENT!!!!!
You have options but being able to take advantage of the them depends on your committment and your Agent's if you choose to use one.