ASUS Technical Support International
Lots of info and help, as well as BIOSes, drivers, Software

ASUS Technical Support Germany
New BIOSes sometimes are available here first

ASUS NetQ Knowledge Base and Discussion Forum
Quite useless, but official. More questions than answers (totally sluggish, at least for me)

ASUS Techref articles
ASUS Techref Monthly FAQ
Here's lots of info, some on A7V problems & solutions, too

alt.comp.periphs.mainboard.asus on GOOGLE.COM (former DejaNews)
THE definitive source of A7V info

Bios Guide by "Adrian's Rojak Pot"
Ever wondered what all those Options do? read it here!

www.conram.com (under construction)
Site dealing with original A7V and CPU compatibility in general. Here's a article in the forum if you want to ask the author questions of want to contribute.

www.braziliantech.com
Extremely useful site :
BIOS modifications (FXD) for lower idle temperature
Some other BIOS fixes (Data Corruption Fixes etc.), RAID BIOSes and Drivers (without hardware changes!), Expert BIOSes etc.
Plus: An archive of all original A7V Family BIOSes
(The site is being reconstructed as far as I know. Above link leads to the Forum, the files are here)

"Crazy Ape's" Page
Info and Files on ATA 100 RAID modification

ANANDTECH Forums
Very Good and very active forums

http://www.athlonmb.com/
Have a look at the Forum here. There's a forum for ASUS motherboards exclusively

http://www.ocworkbench.com/
good and quite active hardware forum !

H-Oda
Some VERY interesting programs to identify Processor Speed, AGP options and to set chipset features
(SoftFSB is mirrored here)

Old Sites:

A7V Tome of Knowledge (not updated since June 2001)
Lots of info and articles, some specialities, too (like data sheets of several A7V components)

http://welcome.to/A7V (site is down, but it's available at archive.org)
A7V FAQ - not 100% up-to-date but very useful

http://www.viahardware.com/ (gone, now it forwards to a site dealing with hardware in general)
Great info for everything VIA related.
Very good Driver installation Guides and newest 4-in-1 Drivers can be found here