Atari computers/homepages:
Hallvard Tangeraas' homepage
Q-Funk's Funkyware
Signus homepage
The Atari Historical Society

Atari ST emulation:
The Atari ST Emulation FAQ
The PaCifiST Official Homepage (ST emulator)
Emulators, Inc. - Gemulator Classic & 98
Chris' Atari ST Pages

Atari 8bit emulation:
Pokey: The Atari 800/800XL/5200 Emulator for MSDOS
Atari 8bit projects and stuff, including XL-It!

Atari emulator software:
Little Green Desktop and Fatal Design
Area 51: For all your 8Bit needs and desires.
The Atari Dungeon

Atari vendors:
B & C ComputerVisions
Ben Smith's Bravo Sierra Computers
Toad Computers
Computer Direct (Canada)
Homa Systems (Canada)