Secrets of Embroidery have some very good tutorials on digitizing with Embird and VIP. Nita's Place as well. Both have clubs to join to allow you to practice your skills and provide ongoing support. I know there are others out there but cannot think of their names. I'm sure others will add to the list. Good luck.

Stitcherymall has some tutorials as well.

I jioned the Flying Needle Studio club

Try this site

Emblibrary.com has some tutorials.

Whoops I got my cart ahead of the horse...didn't read your request thoroughly....don't think they have tutorials for digitizing but just everything else. Sorry

Meganne gave a great site for digitizing help.
Go to her post here:
http://answers.cuteembroidery.com/1149240/EMBIRD-users--lovely-lady-other-group.html

I just got a double CD from a couple of instructors for 4-D digitizing, called Simply 4-D. It is just excellent- super clear, broken down into little chunks, with coffee breaks galore. Best of all, they are stand-alone, so no books to be cross-referencing to all the time!