Deke McClelland made a screencast for Scott Kelby about masking using channels. I just finished Scott Kelby’s book on Photoshop channels. Heed this warning: this 30 minute training video is not for the light-hearted. It’s not for an intro to Photoshop. If you have some decent Photoshop chops, there are a few gems that Deke covers.
btw, if you don’t know who Scott and Deke are, go spend a day on their web pages.
Brusheezy is a killer website with free brushes for Photoshop. You can start by looking at grunge brushes, or watch the video. It’s a bit detailed, but walks you easily through each step. Once you have the new brush, add a new layer in photoshop, click a few times with your cool brush, and change the layer mode to something interesting like Overlay. Enjoy!
How to Download & Install Photoshop Brushes from Brusheezy.com on Vimeo.