Project cars are available on Craigslist or other online classified sites specific to your area. Online auction sites such as eBay are also good sources for project cars.
Car clubs, automotive forums and car shows can also be good places to look for project cars. Members of these kinds of clubs and forums may have suitable project cars available for sale themselves, or they may be able to provide leads for finding one.
Purchasing a car locally allows you to inspect the vehicle personally and make sure it is something you can handle. It also saves the trouble and expense of shipping.