The paint color scheme for the living areas in my house has been troubling me too since I'm nearly finished with wall paper removal in the dining room. I fussed and made a half-hearted attempt to find a color-wheel so I could examine colors and see which ones would be most companionable. I got a decorating book instead, which makes basic suggestions, and has a small picture of color wheel in the introduction. I also realized that compared to getting the layers of paint and wallpaper off of the walls, having the dry wall contractor make repairs, and prepping the trim, the actual painting will be very easy and inexpensive. If I really don't like a color, I can paint it again.
The eureka moment arrived with the Pottery Barn catalog. One of the rugs has reds, blues, yellows, and greens. Those were the colors I wanted and finding the right shades was the challenge. So now, I'm going to use that rug as my palette. I probably won't buy the rug, but I am certainly happy to have picture of it.