http://www.discovergames.com/ Dedicated to helping game inventers and designers find get started and find publishers, or distributers. They also have bulletin boards useful for finding wholesale game parts for your game, or hard to find collectable games
http://www.boardgamegeek.com - Comprehensive searchable database site, full of latest rules translations, reviews & photos.
http://www.sacredchao.cc - Was The Gaming Dumpster and still holds A LOT of rules translations.
http://brettboard.dk - Brett & Board, a new design for the very popular site by Mik Svellov, back in full news flow. An excellent site with up-to-date links and the latest news, translated from Spielplatz. Check out the Essen preview! Try Mik's old site also; http://hjem.get2net.dk/Svellov
http://www.kmwspielplatz.de - all in German.
http://luding.org - Luding, a huge German database, search for game designers etc.
http://www.geocities.com/TimesSquare/Metro/5303/ - Game Central Station, original design for a friendly US gaming group
http://www.io.com/~sos/ - O'Sullivan has reviews and variants.
http://www.clanfork.co.uk/Trev/ - British site with good short reviews and now re-building nicely.
http://home.earthlink.net/~gschloesser/ - Westbank Gamers, lots of game reports
The best websites for English translations are the three above, The Game Cabinet, The Gaming Dumpster and The BoardGame Geek, and Rio Grande Games below has lots of English rules for their editions. But there are places to get rules for English/US games from Hasbro, MB, Parker, Avalon Hill and so on.
http://www.hasbro.com/consumer/instruct.htm - Hasbro is the huge company that has been buying the famous games makers you know. You'll find loads of rules for old games and current games.
http://www.centralconnector.com/ - This site has lots of rules for popular family games you'll find in many homes, missing a few pieces and the rules!
http://www.aardwolfgames.com/ - A good database of rules, especially for Avalon Hill games, published in Germany by Klee.
http://www.compulink.co.uk/~convivium/filelist.htm - This site has rules for Reiner Knizia games.
Internet Game Shops
http://www.riograndegames.com - Lots of English rules at the American centre of the gaming universe, as Jay Tumelson is reprinting US editions of the cream of the German games industry.
http://expages.com/dggames - Discount German Games run by Andy Daglish, selling new German games at German prices, plus postage. Very good list and an active promoter for German games. (previously at http://www.dgg.bigstep.com)
http://www.sfcp.co.uk - Reviews, events and a much reduced price list
http://www.leisuregames.com - Big games shop in Finchley, N London, excellent mail order service, weekly email news.
http://www.spiritgames.co.uk - Wide range and second hand games too
http://www.tgs.co.uk/games/ - Game Store, German Games at reasonable prices.
http://www.adam-spielt.de/index.html - Adam Spielt are the best source for imports, good prices, excellent service, take Visa. A new but difficult website, so send for their cheap catalogue, email them at firstname.lastname@example.org
http://www.stolpmann.de/DrachenneST/ - A good source of odd games, especially Dirk Henn's full range of games always in stock!
http://www.wolfgangs-joker.com - Many older games and will find out of print games.
http://www.scat.demon.co.uk - A wide range of UK and German second-hand games, including your GW and Waddingtons favourites.
http://homepage.ntlworld.com/peterj.keith/mandy/index.html - This was a good 2nd hand games dealer site.
http://www.funagain.com - Very popular US e-retailer, with new games and out-of-print games. Excellent site packed with reviews and photos, well worth a browse.
http://www.bouldergames.com - In Boulder, Colorado. Highly rated US games retailer.
http://www.boardgames.com - Good selection of general games and Avalon Hill
Also try eBay as a good source of games, or UK eBay for the classic British games.