Your best bet is to use a Realtor. Sites like Trulia, Zillow and Yahoo Real Estate are good for information but they lag behind the MLS by anywhere from 2-5 days in most cases. Also, to get sold comparable homes you need access to the MLS. When a home sells we are required to go in and input the purchase price, seller concessions etc. Because Texas is a non-disclosure state you cannot get that information anywhere else.
This is just one of the countless things that a good Realtor does for their clients. Also taking the time to explain and educate them about the market is essential. My job is to educate my clients so they have the information they need to make informed decision. It's your money whether you are buying a house or selling a house. It's my job to ensure that you are making decisions to keep or make as much equity as possible.
Good luck with your search.
REALTOR | Mortgage Broker | Consultant
Buy - Sell - Lease - Invest
Keller Williams Realty | 360 Lending Group