The Encyclopedia of Mythology covers myths from around the world, and also includes folklore and legends. It is an interesting read even if you aren’t doing research.
Another encyclopedia of Philosophy, this provides a number of in depth, peer reviewed, articles on philosophers and their ideas.
This encyclopedia of philosophy, produced by Stanford University, includes articles on ideas and the men behind them.
Adherents is a database containing different types of statistics and information on world religion. This can be anything from percentage of the population that belong to various churches to what the most famous actors and actresses believed.
This BBC site provides an overview of many of the worlds religions. Though not very in-depth, it is a great place to get started or just for a summary.
Beliefnet has resources on many world religions and is presenting in an objective manner.
Explore numerous different Bible translations in English and other languages (including Cherokee), listen to audio versions of the Bible, and find devotionals from a variety of Christian denominations. Bible Gateway also offers a free mobile app for your device, and a variety of reading plans to help you explore the Bible over the course of a year. The site is also accessible en Español.
The PBS series Frontline has a great webpage about Islam discussing everything from the fundamentals of the religion to modern issues.
The Jewish Encyclopedia is an online reproduction of the 1906 encyclopedia of the same name. It is published in full and unedited online. Some articles may be out of date however it is still a great resource.
The Vatican’s official website offers resources such as historic and current papal and council documents, the Bible, and the Catechism of the Catholic Church.