There are already so many excellent tutorials out there for using Photoshop brushes that I decided to do a round up of some of the best for you. By the way, PS Hero, Bittbox and Gwip also have really nice Brush sets.
I just uploaded my Free Brush Sets that you can get via the Facebook page!
Good introduction to loading brush sets and also good tips for managing them.
In this Photoshop Tip I will demonstrate how to change the angle of any brush in the Brushes palette quickly and easily.
Find and Use Free Brushes, Layer Styles, Shapes, and Other Goodies
By Sue Chastain, About.com Guide
Good basic intro to using and making brushes.
Learn more advanced techniques for manipulating brushes such as scattering.
By Photoshop Essentials
Shape dynamics explained further.
Good way to sign your digital artwork or watermark it for social sharing.
Good introduction to making brushes and brush sets.
by Vandelay Design
Nice, clear tutorial.