http://sacred-texts.com for the Key of Solomon, Goetia, Qu’ran, Books of Moses, Havamal and many, many other historic texts. Invaluable for texts of antiquity.
http://www.quareia.com/#main is an incredible achievement. McCarthy here offers a complete, comprehensive and well structured course in magism. This course has the potential to take you from plebeian to adept if you have the will.
http://www.specularium.org/ An excellent source for the Chaos workings of Peter Carroll.
http://www.iotbritishisles.org/ Initiatory Chaos Magic group. Well structured and with a comprehensive approach.
http://www.lunarium.co.uk/calendar/universal.jsp for a lunar calendar.
http://www.tomegatherion.co.uk/home.htm A great guide to various aspects of the occult, groups and symbolism. Far from being the ultimate resource, it is however a comprehensive guide and launch pad.
http://www.ancient-symbols.com/ is a well researched and structured resource for all esoteric and religious symbolism.
http://www.hermetics.org/library/Library_Grimoires.html Is a great resource for Hermetic texts and study.
http://www.esotericarchives.com/esoteric.htm is another amazing source of texts from antiquity. If you need an ancient occult text, then it is likely here.