Here is a link for books by Zac Poonen free to read online.http://www.cfcindia.com/web/mainpages/bookshelf.phpAlso here is a link for some of K.P. Yohannan's books free to read or download in PDF format.http://www.gfa.org/resource/
Here's a link to a Website I found today with full copies of free books online (incl. "Classics").http://www.fullbooks.com/Have Fun!Love-in-Christ,KP
I am in the exact same situation! I am reading Pilgrims Progress right now! I think I acquired it via ccel but cannot remember. Definitely echo what InTheLight said as far as "who" to read. Most Puritan writings have been reduced to mere tracts today. A sad loss for the faith. You have been given some great resources already, but simply google the name of a book and type "pdf" at the end and see what you get!
I can also recommend "Deeper Experiences of Famous Christians." I have uploaded it to Scrib and you can find it here:http://www.scribd.com/doc/62621076/Deeper-Experiences-of-Famous-ChristiansI also recommend "The Three-Fold Secret of the Holy Spirit" by James McConkey. It can be found here:http://www.scribd.com/doc/82870504/The-Three-Fold-Secret-of-the-Spirit-by-James-McConkeyThere are also many many good Christian books to found at Christian Classics Ethereal Library:http://www.ccel.org/read
http://www.plough.com/ebooks/wisdomofthesadhu.html Some writings of Sundar Singh. Very refreshing.
What Every Christian Should Know about the Supernaturalhttp://www.victory4you.net/what-every-christian/The Bible, The Supernatural and the Jewshttp://www.victory4you.net/bible-supernatural-jews-2/Pilgrim