Hi, Red Moon!
Do you have the Little White Book that came with the deck? It actually does a pretty good job of explaining the Egyptian symbolism that appears on the Major Arcana. However, as with most Little White Books, the Minor Arcana are pretty much ignored.
I can give you this website, which I got from another thread somewhere here on Aeclectic:
www.kemet.org lists the Egyptian deities and a little of their background.
Almost any good beginner book on the Rider Waite would cover the Majors pretty well. Phoenix's recommendations are excellent choices!
As for the Minors, there's more Kabbala corresponces, etc. in these cards than I know about. So if someone knows a good beginning reference on that aspect, I'd love to know about it, too!
Actually I've learned most of the little I know about Kabbala (this spelling is used in the Ibis' LWB) from the Tarot Magic Computer Program! There are quite a few good essays on the historical aspects of the Kabbala
Good luck with the Ibis!
Peace,
Melvis