I would say 3/4 hours is sufficient to get you up and running, but that you would need telephone support from Diabetic nurses should you need it for things like changing your basal rates etc or say you've forgotten how to do something.
They come with very good manuals on how to use them. I was ok with using them, but found the set change hardest (mainly loading the insulin etc) but after 4 weeks, it's fine and I'm not nervous.
To be honest, I think it's better to learn as you go. 3/4 hours is all I had for my son's pump and it was enough to start with. Any more and I think it would have gone in one ear, out the other!
Clorinda