I'd like to point you to a white paper that Eric, one of our program managers, did on Indexed Views in SQL 2005. This logic mostly applies to the Enterprise Edition of our product.
This white paper focuses on the functionality in our product. If you have questions or things that we can make clearer, please let us know and we'll roll them up into the next revision of this (that goes for any of our published works, btw).
I'll try to put together some additional literature on indexed views/materialized views from the academic literature, as this is a topic that can take some time to digest.