I want to install recessed light in a ground floor family room.

the room is 20 x 20 with 8 ft ceiling. What spacing should the lights be for reading and what wattage.

No need for wall wash

Incandescent or fluorescent?

Someone else had found this website, I thought it illustrated fairly well:
How to layout Recessed Lighting Cans or High Hats (http://www.forteelectric.com/Howtolayoutcans.html)