Finding Data on Selling Price History

[Brian Mathews]

Could anyone recommend a good source of information on the history of prices on single family homes in a local area?  I have read books that recommend comparing properties you are thinking about buying with similar properties that have sold in the same area.  I think it would also be useful to find historical trends on property values. Nothing I have read is very clear on the actual process of doing the recommended research.  Any help would be appreciated.