Astrology.net This is iVillage's Astrology mega-site. "The ultimate guide to exploring astrology, daily horoscopes, love astrology, chinese astrology, zodiac signs, compatibility, and more!" I use it mainly because it has the most thorough explaination of occidental astrology I've found online. You can learn about the houses, planets, aspects, all that funny vocab, and pretty much figure out how to read a natal chart on your own, for free, in just a few hours. They also have a weekly newsletter to report recent current influences.
Astrodienst This site offers very well done free natal charts in gif format. Charts show the position of the sun, moon, all the planets, your ascendant, MC, and trine node. (For those of you who don't know about natal charts, they are the very foundation of astrology--a picture of the planetary positions at the exact minute of your birth, which shows what influences the planets have on your personality.)
Astro Readings offers free cycle and influence dates based on your chart and current astrological occurances. They also offer free Personalized Readings, Natal Charts, Relationship Analysis, Horary, and Electional charts.
Astrology World A collection of articles on astrology, plus web freebies, a club, debates, an "atro-mall", and links.
Astrozine.com "Free Celebrity Astrology & Horoscopes." Natal charts and readings of celebrities.
Astrology Alive - Holistic Astrology "Free Horoscopes, astrology articles, a bookstore with 1000+ astrology books, chat, a bulletin board, a Consumers Guide to Professional Astrology, a SkyWatch page of upcoming astrological phenomena, and a forecast for the Mid-Life (37-47 age group). Computer-generated astrological reports, PalmPilot astrology, astrology consultation via Internet Phone, resources - including international professional journals and organizations - astrological software, recommended books, and loads of links complete the package."
Astrologer.com Metalog "Metalog is home to the International Directory of Consulting Astrologers, formerly known as the Metalog Yellow Pages, as well as the websites of the Astrological Association of Great Britain and the Centre for Psychological Astrology." You can input your location and get the perfect astrologer, association, school, bookseller, merchandiser, publication, writer, or researcher for you.
Asian Astrology Pages Chinese, Tibetan, Vietnamese astrology methods. Produced by William L. Cassidy, life member and patron, Tibetan Medical and Astrological Institute.
(The following websites are commerical, offering software, chart readings, and other astrology-related products.)
theStarGazer.com Complete low-cost chart readings. I give my word these are very high quality. I've gotten them myself, and I'm extremely happy with them. Only about US$7.00 for the main reading! Plus, lots of astrology-related goodies (stationary, mobiles, etc.), great for presents.