Any good websites for wire derating, conduit fill, motors and transformers? Tutorials or something...

Especially derating & conduit fill. I remember that, and basic 3 phase ohms law was the most predominant when I took the J test.

Trying to help a buddy.

Derating and conduit fill are right in the code book. And most other calculations can be found in an Uglys.

If you don't know "Uglys" is a good book every electrician and apprentice should have.

You can get it here or most major book stores have it along with many supply houses.

Mopar man, how about just coming up with a few scenarios for your friend to calculate numbers for, such as a made-up house or two, a couple of industrial machines and feeders, etc?

You might want to go to www.mikeholt.com
There are practice tests at that site plus a world of information and study guides for sale.

The Illustrated guide to the NEC is good as well as Commercial Electrical wiring. Both available at Mike Holt, like luckyshawdow said.