Noel, Trulia is a good spot but the Office of Federal Housing Enterprise Oversight is another. Their web site is OFHEO.org. They use appraisal information and has all the MSA's for major urban areas. Check with your local Statewide Realtor Association and local MLS as they all have data which a local Realtor can access for you.
We don't show this information by state but we do by city. For example if you access the link below you'll see our San Francisco Real Estate Guide and you can interact with the graph to compare median sales price across different periods.