ATLA: American Theological Library Association
ATLA is supported by EBSCOhost (epnet.com)- world's premium research database service. It serves thousands of libraries and other institutions with premium content in many subject areas. Includes journal, book and article search capability. Very comprehensive.
A keyword approach to searching 7 different versions of the bible.
Comparative Religion: A Directory of Internet Resources for the Academic Study of Religion
A massive site with all manner of information from bibliographies, concordances, dictionaries, texts and links to hundreds of other sites on all religions. It lists several Internet guides to religion.
Religion on the Web
The easy to use index provides ample access to non-Christian religions as well as links to the author's sections on Philosophy of Religion, Individual Philosophers and Scepticism for the non-believer.
Voice of the Shuttle: Religion
As ever the VoS web site is very comprehensive. Depending on your field of interest you may also wish to look at the VoS sections on History and Classical Studies. Simply click on the VoS home page icon to get a list of all the main sections.