Ooh.. I can't, because I'm self-taught, I first started by creating a MC skin with GIMP, coloring over.. just messing about. I first started playing with MC for the mods, than I found some modders to test my texturing abilities. It takes time, and I was really bad at the beginning. The "Colorize" and the "Noise Generator" tools are some of the best things to mess with at the beginning of texturing. Take a MC skin, and start with that, or try retexturing Vanilla, and ask for help/input regarding that. GIMP is a free alternative to Photoshop, and is quite powerful.