There is lots of information out there if you are willing to look for it. One way to wade through the information to find what you are looking for is to open the website and hold down ctrl and F - this brings up a Find bar on the web page. You can type in anything you are looking for ie. Isis. and if it is in the text then it will find and highlight it for you. Amazing! 

Project Guttenberg Books - free to use

On the Nature of Things by Titus Lucretius Carus - http://www.gutenberg.org/files/785/785-h/785-h.htm

Meditations by Emperor of Rome Marcus Aurelius - http://www.gutenberg.org/files/2680/2680-h/2680-h.htm

The Aeneid by Virgil - http://www.gutenberg.org/files/228/228-h/228-h.htm

The Metamorphoses of Ovid, Books I-VII by Ovid - http://www.gutenberg.org/files/21765/21765-h/files/Met_I-III.html

The Metamorphoses of Ovid, Books VIII-XV by Ovid - http://www.gutenberg.org/files/26073/26073-h/Met_VIII-XI.html

The Golden Asse by Lucius Apuleius - http://www.gutenberg.org/files/1666/1666-h/1666-h.htm

The Religion of Ancient Rome by Cyril Bailey - http://www.gutenberg.org/files/18564/18564-h/18564-h.htm

The Conflict of Religions in the Early Roman Empire by T. R. Glover - http://www.gutenberg.org/files/39092/39092-h/39092-h.htm

The Religious Experience of the Roman People by W. Warde Fowler - http://www.gutenberg.org/files/23349/23349-h/23349-h.htm

The Oriental Religions in Roman Paganism by Franz Valery Marie Cumont - http://www.gutenberg.org/files/22213/22213-h/22213-h.htm

Myths and Legends of Ancient Greece and Rome by E.M. Berens - http://www.gutenberg.org/files/22381/22381-h/22381-h.htm

The Common People of Ancient Rome by Frank Frost Abbott - http://www.gutenberg.org/files/13226/13226-h/13226-h.htm

Ancient Rome : from the earliest times down to 476 A. D. by Robert Franklin Pennell - http://www.gutenberg.org/files/6989/6989-h/6989-h.htm

Ancient Rome by Mary Agnes Hamilton - http://www.gutenberg.org/files/34025/34025-h/34025-h.htm

Roman Antiquities, and Ancient Mythology by Charles K. Dillaway - http://www.gutenberg.org/files/20734/20734-h/20734-h.htm

The Religion of Numa by Jesse Benedict Carter - http://www.gutenberg.org/files/18222/18222-h/18222-h.htm