Here you can find brushes and related downloads. There are also a few brushes on the Daily Download page.
Note: Lynda.com has several free video tutorials including a few on brush basics on this page. There is also a nice basic brush settings article on SmashingMagazine here.
Use FileSavr link if possible (saves our bandwidth) otherwise click on the .
I've gotten a few emails from people who wanted to know how to use these brushes to create realistic surfaces. I created a quick video that shows a few techniques. It is raw and unedited but should give you a few ideas. Please let me know if you find it helpful.