Hi Robert,
Wireframe Group are the ones that do tutorials for XPression, however, they're not cheap ($999 for a tutorial DVD with 22 tutorials on it). I haven't got them myself, but I believe they're very comprehensive and worth the money, especially if you get new operators later and don't want to get a Ross trainer out again or have time to train them yourself.
Their website is
http://www.groupewireframe.com
If you sign up on their website (for free), you can download a sample XPression project. I used this, along with the sample project from Ross, to work out how to use XPression, and I've become quite accomplished at it, I think.
James.
#XPression