The developer Imagineer Systems website hosts a lot of how to do's free of charge.
Have a look here:
http://www.imagineersystems.com/videos?tagFilter=%25tutorial&sortBy=Newest
Also have a look here:
http://www.imagineersystems.com/videos?tagFilter=%25learnmocha&sortBy=Newes...
You can view them online, save them and a few of them even have source-files you can work with. Mocha and Mocha Pro are quite easy to get into once you get your mind around how it works. Brilliant software for rotoscope-work.
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Erik Lindahl
Freecloud Post Production Services
http://www.freecloud.se