i think this tutorial will help you out on sculpting and modeling organic and hardsurface props https://www.thegnomonworkshop.com/tutorials/creature-modeling-for-production
poopinmymouth's character tutorials are really good he has video tutorials that include moveable eyes and a moveable mouth. check it out www.poopinmymouth.com
There's Ed Harriss's website (http://www.edharriss.com/), and the large number of tutorials that come with XSI itself. Check www.xsibase.com should have tutorials also.
BenHenry use this: vtools and there is a brief tutorial on how to set them up here: http://www.nextgenhardsurface.com you have to sign up to see the tutorial.