What is the "rule" as for how many wood species should be in one house? We have American Cherry in the family room, solid oak with cherry stain on the stairs going into the living room and would like to install Brazilian Cherry in the living room, but are concerned about re-sale value of the home. This is a quad-level home with each wood species on a different level.

Ideally you want the floor materials to flow through the space so that when you look at the floor it is unified. This doesn't mean you can't use different materials, but I couldn't break up the types of wood too much. While I love Brazilian cherry, I think you're better off with an oak with a cherry stain, like what's nearby.

Here's a link I found that shows different floors--can give you some good tips on selecting the right floor.

http://www.oldhouseweb.com/stories/Detailed/13401.shtml