LDS Religious Studies Center
The digital collection of the
Religious Studies Center
. Has quite a lot of books freely available in pdf format. For example
Apocryphal writings and the Latter-day Saints
Deity & death : selected symposium papers
Helaman through 3 Nephi 8: papers from the seventh annual Book of Mormon Symposium, 1992
The temple in antiquity: ancient records and modern perspectives
Religion, mental health, and the Latter-day Saints
Its surprising how much material is available, free.