You'll have to learn a lot of stuff by hand - typing out spell lists, etc.
The IRC channel is your best bet as far as getting questions answered as they come up.
There is also a strategy wiki page you can search for with some of the basics listed.
EDIT - Additionally, there is a walk-through for Dominions 2 by the writer of the manual for Dominions 3 that you can find in the downloads section, I believe, which will answer a lot of "start-up" questions.
Here is the download page for Dominions 2