The usenet newsgroup comp.sys.ibm.pc.games.strategic, here you can find many articles about Dominions and many other strategy games as well. It can be reached from google groups if you don't have a newsreader.
Dominions X, a web site with Dominions related material and a Dominions forum.
Philippe Sacre's excellent Dominions Library. You can find plenty of information here.
Gandalf Parker's library of daily generated random maps. These maps are avaialable in three different sizes.
Dominions spells converted to the Ars Magica role playing game.
By Alex Poger
Here is a starting tutorial for Dominions written by Alex Poger. It can be very useful for new players. It explains how to create a competitive god and the basic strategies you need to survive.
Download Alexander's Guide to Getting Started in Dominions here: start_guide.pdf
Excel Spell List
By Björn Loesing
Here is a list of all available spells in the form of an excel document. This document was contributed by Björn Loesing and the spells can be sorted in any way you like.
Excel Spell List: domspells.xls
Java Spell Navigator
This java application lets you search and sort spells in a database like manner. It was contributed by Gordon.
Java Spell Navigator: javaspells.zip
Excel Site Search Table
An excel table suitable for keeping track of which provinces have been searched for what kind of magic. This document was contributed by David. Check the info tab if you have any trouble printing it.
Excel Site Search Table: sitechecklist.xls