We have also recently acquired Manikin but I haven't found much documentation either.
According to PTC from the faq on this site link:
"Are training courses available for Creo Elements/Pro Manikin customers?
Instructor-led onsite training and/or Web-based training courses will be available for Creo Elements/Pro Manikin customers in the future. The most up-to-date information can be found on <u>PTC.com</u>.
In addition, a complete tutorial is included with Creo Elements/Pro Manikin Extension"
Sure would be nice to find this tutorial. Unless I've overlooked, it isn't in the ptc_manikin_lib download.