Links:
John's Arcade
John's personal arcade website and home of the unofficial Nintendo Vs. Tech page. You'll find all you'll need to know about the Vs. System including a game list, PPU and chip compatibility, instruction manuals, dip switch settings, etc. You'll also find videos of most of the Vs. games he owns. A valuable resource!
Playchoice Games & Resources
Although it's mainly a Playchoice-10 site, there's a great section that has info and artwork references for many of the Vs. titles.
Arcadeflyers.com
Excellent resource for arcade flyers. The link above goes directly to the Nintendo Vs. flyers that they have in their database.
The Arcade Cup
Do your Red Tent 18" Sharp XM-1801 monitors need to be fixed and you don't know how to fix them? Chad is a cool guy who fixes monitors. Check out what the Monitor Boss has to offer at The Arcade Cup.
KLOV / VAPS
The Killer List of Video Games + Video Arcade Preservation Society = Video Game/Pinball database, resource and community.