I'm teaching myself to texture, and its very satifying when texturing something,
If you want to texture, I can offer this advice;
Use an application like The Gimp, Photoshop or Paintshop pro, The Gimp is free, and the texture you want to make, look at something (an image or object) with that texture, and think of is as layers, like how I tackle metal, the bottom layer looks cloudy, so I use Photoshop's cloud filter for layer 1, then there seems to be some noise and dots, then I use the noise filter and add little details, the next layer is scratches and so on.