I too have been struggling to learn Rhino for jewellery & have found Moi much easier to learn.
I'd been using the Rhino Jewellery Tutorials from CadWax to start learning in Rhino3, they where free at the time. http://www.cadwax.com/default.htm
I then found that I could use most of these instructions for designing jewellery in Moi.
There's some specific tools & things that only apply to Rhino, but it does give you a good starting point.
