Other Sites of Note
I've trolled the web for the best Dune sites and found that
many links provided are broken, fairly useless, or simply
have nothing to do with the game. Here are what I believe
to be the most relevant and useful sites for the Dune
Boardgame Geek's Dune Entry
One of the best sources for anything game related. BGG has an extensive list of files, scans, reports, reviews and on and on regarding Dune.
Colin's Dune Page
Colin has an excellent archive of scanned images for those who need to replace parts for their Dune set.
Boycat's Variant Variants
While those who know me understand that I avoid variants, expansions and house rules like the proverbial plague. Nevertheless, Boycat's versions of the Ix, Landsraad and Tleilaxu variants are worth documenting.
(Note that I have not played these rules, so this I provide this link as an FYI rather than a recommendation)
Yahoo Dune Group
Not much seems to be going on with this group this year (2008), but it is still a useful link to have. They are mainly concerned with PBEM games, but have two files in their archive of great interest - eMail correspondence with Peter Olatka and Jack Kittredge (two of the designers of Dune).
Avalon Hill General Archive
This site, claiming to be not-for-profit, is attempting to archive all information from all of the General magazines. They have much of it already available on CD. More importantly - they have reproduced Dune bits, cards, boards and such in high resolution on high-quality material. Be sure to check them out if you are missing some bits or just want to replace your worn-out pieces.
I've linked directly to the sweet bits, but you can click on 'home' to see what else they have to offer.