Loot - the best South African online bookstore, they've got everything you csn think of with great prices and quick delivery. South Africans, always go here before you go to Amazon!
Vedic Books - also South African, an incredible bookstore for all things Vedic. Amazing prices, great service, books you'll find nowhere else...
Amazon.com - granddaddy of the online bookstores, VERY expensive shipping fees but they've got everything.
Alibris - great for hard to find and second hand books.
AstroAmerica - the most astonishing astrology bookshop on the net - superb catalog, great prices, reasonable and fast shipping rates.
Skyscript - excellent resource for serious astrologers, great material for beginners, head and shoulders above all the astrology sites out there.
Astrodienst - still the place to go for online charts and to download more ephemerides for Solar Fire and other software, also has excellent articles.
AstroClock - the "live" astrology clock I wrote and distribute freely. thousands of people all over the world use and love it - get one for yourself!
GoVeg - an excellent resource on the hows and whys of vegetarianism.
Andrew Weil's website - great resource on sensible, healthy living.