Hiya.

I use my Wacom tablets (oldies but goodies; a 6"x8" and a 12"x12", both old serial ArtZ II's). I do 'scan' some stuff in, but usually end up using the scan as a sort of 'guideline', and re-draw it in the computer. For actual texturing asset creation, just use digital photos, and learn to use Photoshop/PaintShopPro/GIMP/Painter/Whatever to blend and mix pictures together.

I'm sure there are tutorials out there for doing all three (hand draw, scan, digital pics). Good luck!