Really depends on how much you already know about Poser.  I bought my nephews Poser 9 in 2012 for Christmas.  I also upgraded them to Poser 10 this Christmas.  At thanksgiving they had a ton of questions about how to do a lot of things in 9.  To help with all the things they needed help with I bought the Infinite Skills training from Amazon (which by the title I believe is the same one) which you are asking about.

It covers a lot and I even got a couple tips out of it.  There are a couple of very small issues with what is covered and the current version of Poser, the training is based on a prerelease version and is also done on a MAC.  It will not make you an expert on any one subject, but does go over all the programs features with exercises to make you do the task and do for yourself what is being discussed. 

As I said it depends on how much you already know.  I know the principles of rigging but the demo of how to rig a model was fairly well done and explained a couple issues that I had not even thought about.  So I personally think it a good buy.

 

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13