This thread in Polycount has a TON of great tutorials. It looks to be mostly for gaming, but they are great to view. If you are needing help with texturing for games or pixel art, this is definitely the place for you. There are also some other great links that will take you to things such as hotkey guides for zbrush and project breakdowns, among other things. If you know about the greatness that is pintrest, this thread will lead you to links of peoples pintrest who have collected great resources. Big thanks to Niuva of polycount who did this. Check out their great collection.