What you're actually going to be doing is Intarsia, and the thing that really made Intarsia click with me was when I read "when you start a different color, make sure you bring the yarn up under the color you were just using." This causes the yarn you are switching from to be caught in the next stitch, and that prevents holes in your work where you are switching colors. It's really quite simple & elegant once you get the hang of it. You'll have short vertical stitches of color on the back side of your work, and that's how you'll know it's working out OK!!
Julie | I'm Dotmom on Ravelry.com, too.
Not everything that can be counted counts, and not everything that counts can be counted. | Albert Einstein