Does anyone know how or why or how to stop google from indexing products from my other sites. I have 2 sites one selling shoes and one selling electronics. Huge difference. Google is finding electronics on my shoe site even though there are no links. WHY?!?!?

Please Help. Open to any input whatsoever.

Also could use help on that search problem than many others are having. I can't have a search for "black" on the shoe site bring up black electronics.

Thanks