You also need to check an actual swatch in the lighting of your room. Even though I pick paints for a living, I chose a color called pewter for my mudroom, thinking it was a pretty pale silver.... ummmm.... its pale lavendar in the mudroom because I have flourescent lighting in there instead of incandescent. The difference in lighting was enough to hide the purple tones under the yellowish incandescent light, but the bright white of flourescent showed up all the purple tones. If anyone should know better about choosing colors in hte room theyr're intended for, its me! Oh well, I'll repaint again in the spring

Oh, and to answer your question, Ben Moore has a great site Ben Moore

As for paint chips, you can pick them up anywhere: Wal Mart, Sears, Lowes, Home Depot.... basically anyone who sells paint.