I guess it's about time to tell you what I am trying to do.
I have a number of toroids of different sizes. I want to put 20 turns on eash one and measyre the inductance produced. The problem, which I didn't think out very carefully, was that the only AC source I have produces, according to the VOM, a little more than 14 volts. But that doesn't really matter does it? I'm going to be measuring with an LC meter. I doubt it will blow anything up.
But, this has not been a waste of time. The numbers and guidelines you have provided are valuable. I never really considered it before, but I have had some test leads get pretty toasty. I think I need to make a set with larger conductors and start being more concious of circuit currents.
The magnet wire data is also important because I'm slowly trying to move into the RF world, and the ability to create my own inductors is probably going to be important.