Bronze Age Miniatures
Great Barsoom-like miniatures.

Parroom Station Net
The link above will drop you into the store; the site is hard to negotiate. I don't find these as nice as the Bronze Age Minis, but there are some that can help fill the gaps.

WebBooks of the Edgar Rice Burroughs Barsoom series.
If you don't want to spend the money on the books, read them for free at the link above.

Information & News
John Carter of Mars Official Site from Edgar Rice Burroughs, Inc.

ERB List
The Life and Works of Edgar Rice Burroughs, Creator of Tarzan and Barsoom.

Encyclopedia Barsoomia Wiki
Another handy resource on all things Barsoom.

A Barsoom Glossary
A handy glossary for all things Barsoom.

John Carter of Mars The Feature Film - Unofficial Fan Site: Loaded with news and information on the feature film and more.