Wikipedia: Sega SG-1000 - Information on the Sega Game 1000 includes history, emulation, and versions. - http://en.wikipedia.org/wiki/SG-1000
MobyGames - Sega Master System - List of games with screen shots and reviews. - http://www.mobygames.com/browse/games/sega-master-system/
SMS Tributes - Offers game database, cheats, screenshots, reviews, and downloads. - http://www.smstributes.co.uk
The RetroVault - Offers cheats, downloads, and images. - http://www.retrovault.com
JAG's Video Game Zone: Sega Master System - Offers game, hardware and advertisement images and reviews plus system specifications. - http://www.emucamp.com/jagsvgz/systems/sms/
SMScene - Reviews, technical information, emulators, game midi files, scans, ROMs, FAQs, cheats, lists, guides, history and links. - http://www.emucamp.com/smscene/smscene.htm
GameFAQs: Master System - FAQs, codes, message boards, reviews and game data. - http://www.gamefaqs.com/console/sms/index.html
UK Sega Master System Page - History, information, specifications, a FAQ, and links. - http://www.severedbbs.u-net.com/fletcher/SMS.html
Sega Master System Museum - Game screen shots, user reviews, FAQs, hardware information and images, magazine ads, japanese game ad movies, personal collection, links. - http://alexkidd.com
SMS Power - News, ROMs, old releases, forum, and links. - http://www.smspower.org/