“These 28 videos tutorial series will teach you how to get started in ZBrush. These tutorials created by the Pixologic (makers of ZBrush) for the 3D community, so everyone can easily get started in ZBrush, a powerful program. Click on the below images to play that video. As always you can also download the files in flv format for later viewing.”
http://www.cgarena.com/freestuff/tutorials/zbrush/pixozbrush/index.html