The other day I came across a great resource for those interested in religion. The Ocean World Religions Free Research Library is a collection of more than a 1000 documents associated with the religions of the world, including the Baha'i Faith and Zoroastrianism.
Personally, I'm finding it particularly helpful at the moment in regards to the Baha'i Faith, which is rooted in the numerous writings of its founders and early leaders, which I've been having difficulty acquiring through other means.
It is a large file to download: about 24 MB. If you don't have a high speed Internet connection, they can mail you a copy on disk for $5 to cover shipping.