There are several sites on the net which offer spiritual classics as free ebooks.
EWTN has a library of resources, this one, which has articles, has a section on Cults and New Age
EWTN Library files
Here is the main EWTN Library page, you can select a category, and press 'search' or you can search for a book by title or author
EWTN Main Library page
Here are some older books, which many have found helpful in their spiritual life
Catholic Planet ebooks
Another great resource with loads of good reading is provided by Calvin College which looks to be non-Catholic, but they do have Chesterton's books and all the great classics and Church Fathers. Go to the browse tab and search by title, author or category
Christian Classics
Slightly more theological, though you will find all Chesterton's books, and in PDF form (so you need Acrobat to read them) is
His Mercy ebooks
I do hope you will take a look at some good solid spiritual food. The Bible is available online in many translations. It is the most important Christian written resource of all, so don't forget it! ;)