Thanks for your question. In order to be on MLS, you would need your home to be listed by an MLS listed Broker. There are limited service company's that for a fee will list your home on MLS. However, when you are listed on MLS, you are agreeing to offer compensation to a broker who finds the buyer. Going on your own, Trulia and Zillow seem to be the best for for sale by owner.
Keep in mind, just being on MLS, in my experience, isn't all you need to get your home sold. There isn't an agent pushing your property, taking nice photos, updating them, asking buyers and agents to show it and make an offer. And more importantly, when you do get an offer, there isn't an agent with experience in negotiating and knowing market comps to help you. In a for sale by owner there isn't an agent to help you get through the inspection with their expertise and guidance or to get you to close with title and issues that come up, and they always come up.
Also you will find a lot of MLS listed agents and brokers don't want to show their buyers FSBOs because they end up doing twice the work and getting paid for less than half.
Hope this helps. If you find that FSBO isn't what you hoped, give me a call, I have 10 years experience and 100's of closed transactions.
Bay View Homes