Joe did a great tutorial on editing your images with GIMP, which is free photo editing software. This is the one area that I feel most bloggers need help with, post editing of images prior to putting them up on their blog/Facebook/whatever. It really makes a HUGE difference, and Joe walks you through it in this tutorial.
Dave does really great tutorials, it’s kind of his thing, and this one is no exception. If you ever paint white or yellow, then definitely check out Dave’s tips on working with those colors. In fact, the tips are universally useful regardless of the colors you commonly paint with. He also did a great short video showing exactly how he does it.