David Richardson has created a multiple-part tutorial for modeling a mech in ZBrush.
2 New ZBrush Character Production DVD Releases by Michael Pavlovich
Eat 3D have released two new ZBrush character production DVDs by Michael Pavlovich.
Cyborg Design - Concept Art Production Techniques
Instructor Michael Pedro gives a detailed overview on concept art production techniques in ZBrush and Photoshop.
ZBrush 4R5 - Making Time for Art - The Dragon Flyer
The cool new features of ZBrush 4R5 are demonstrated in this video by Pixologic.