How to Paint Rocks in Photoshop
Marc Brunet shares a free video tutorial on how to paint rocks in Photoshop.
Free Photoshop Brushes
Several professional artists have made available their Photoshop brushes for free.
Art for Games - Memory Folds in Clothing Tutorial
Art for Games have posted a free tutorial on creating memory folds in cloth, using ZBrush and Photosohp.