As for colored pencils, prismacolor pencils are really good. You can of course get higher-end colored pencils, but the prismacolor are still heads and shoulders above your basic crayola or store brand. They are a little more pricey, but the feel of the line is so much smoother, the colors lay down more evenly and richly on the paper. Good for shading and blending.
I think you can get a 12-count on amazon for like $10 or a 24-count for like $16. With blending, you probably don't need many more than 12 or 24 colors anyway.
One thing that's tricky about colored pencils is that you cannot paint over or draw over with a lighter color, and you can't really erase completely. So if you make a mistake and color something too darkly, you can use an eraser to lighten it up, but you can never get it back to pure white. I suppose you could go over it with white chalk, but you'd need to use a spray sealer so the chalk doesn't smudge/brush off.
This same property is true of watercolors and markers to an even greater extent. Acrylic and oil paints you could paint over with white or a light color. But, of all of these mediums, I'd say colored pencils have the easiest learning curve.