Go to http://www.forsalebyowner.com It is set up for sale by owner. I do not know what it charges, but it is the biggest for sale by owner site on the net.
My first suggestion would be to have a Realtor do a current market analysis for you. This should be done to determine the true current market value of your home. Secondly, you will benefit greatly by having your home on the Multiple Listing Service in your market. For this you will need to use a Realtor or real estate professional in most areas. This will give you the best instant exposure to all agents and their clients who are your buyers. If you choose to try and list the property for sale by owner you will have fewer areas of exposure but can be done. Try listing on the internet at sites like craigslist.org, zillow.com, realtor.com or here on trulia.com. All of these will give you access to buyers but unless you have a knowledge of the real estate business and paperwork involved or have an attorney who will check all your documents I would call on a Realtor for help. You will incur some expenses (their commission) for the services they provide but this is what we do for a living and can give you the best current advice. I wish you success in your real estate endeavors.