Annice, these usually are fairly specific by builder/architect. Is there a specific one you are looking for?
Annice are you looking for sample floor plans for single family homes? There are several stock floor plans you can find online these days. Type "floor plans for single family homes " on Google. Here are a few - http://www.houseplangallery.com/index_files/index.php
If you are planning on building from scratch by your self then hire an architect or a builder after you have found an ideal floor plan that suits your requirements. Good Luck!
What type of house are you looking for? I know several architects in the area that sell plans for reuse.
Here is a hometalker that creates floor plans- http://www.hometalk.com/member/4cf4ca8983