Ben Mauro has posted a ZBrush video tutorial, focusing on the development of his Yukon Pit Crew project.
ZScripting with ZBrush - Eat 3D Tutorial
Eat 3D have released a video tutorial on ZScripting with ZBrush.
David Richardson - Mech ZBrush Tutorial
David Richardson has created a multiple-part tutorial for modeling a mech in ZBrush.
Eat 3D - ZBrush 4 R2&R3 - New Features - A Comprehensive Overview
Eat 3D present a tutorial DVD by Michael Pavlovich, featuring a comprehensive overview of Zbrush 4 R2&R3.