I’ve figured out a few methods that work pretty well.  One way is to just go on flickr, type in a nearby town name followed by “abandoned”.  Theres also a map feature, so if people geotag a spot you can find it.  To do that, go here, put in the name of your county, or nearby counties, and make the search term “abandoned”.  A lot of places I find just by driving around.  Rural areas have a lot of abandoned houses, and its usually less risky to go to those since there arent as many people around to catch you.  Look out for long grass, broken windows, etc. Bing maps has a cool feature which is “birds eye view”.  Its basically 3/4th view, so if you know what youre looking for you can find abandoned houses that way too.  Basically just look for holes in the roof or broken windows, or over run driveways.