There are various whitetail butchering charts available. I found this one at http://www.alfredny.biz/sportsmen/Whitetail-yield-chart.htmby searching on "whitetail butchering chart"... there were many more listed that you may like better.

I think it's mostly a trial and error sort of situation, but a chart is probably a good place to start for reference. Better yet, helping someone else who is experienced in it is even better.

As far as a grinder.. like statjunk said, get a good one otherwise you'll simply end up buying multiple ones and paying more than you should. The small motored cheaper units are made for very small time grinding and if pushed will burn out quickly.

Hope that helps!