Bird dogging is a way to bring more exposure to your real estate investing business.  A bird dog is a person who locates properties based on your specifications, e.g.  vacant homes.  As an investor you ask your family and friends to let you know if they run across a vacant home.  If you close the deal you pay them a fee for finding the house.  A bird dog can also be someone who you get to find the home, take pictures, and any other preliminary leg work you may need for a small fee.  You tell them that they get paid on the closing of the deal. 

I would agree with Brad on checking with your local and state laws on this.  We aren't attorney's and can't give legal advice.  Brad is also correct in that flipping contracts is another name of wholesaling.  You get a property under contract and "flip" the contract to the home to another investor who may want to rehab the home.  Flipping contracts is a good way to get income to build a base to move to rehabs or becoming a landlord.    I hope this is helpful.  God Bless!

Daren