tutorial:
http://www.youtube.com/playlist?list=PLyLDNgBXVMfTDsCAgndbmNPdtJPaGo92n
Other steps starting from a simple blender model to zbrush:
https://www.facebook.com/blenderWorks/photos/a.605761326169502.1073741938.132831550129151/606382422774059/?type=3&theater
