www.rapturetruth.net/home.html  I like this site.  The author has stated right up front that the idea of the "rapture" taking place before the "tribulation" period is just so much bunk.  The author of this site says he has been trying teaching the error of this "rapture" doctrine for years.  He is not alone. This is not an original truth as this has been recognized as a false doctrine for hundreds of years -- It has only entered into the fade, or popular feel good doctrines that have found fertile ground and has been flooding into the feel good religion of Christianity.  I call this pre-trib rapture doctrine the "escape doctrine".  There is a human desire to not have to suffer and this false doctrine offers just that.  Check this site out, lots of truth and solid bible study there. 

www.endtimeinsight.com.  This site by Steve Wohlberg, author of the book, End Time DELUSIONS. 

www.the-cutting-edge.org   At this site you may be able to obtain a copy of the book,  "The Incredible Cover-up, The True Story of the Pre-Trib Rapture", by Dave MacPherson.  This is a 1974 title mention on one of my papers on the "Left Behind Lie"

http://www.libertytothecaptives.net/  Want a FREE book?  You just pay the postage of $2.13 for the book "God's Wrath on Left Behind" by Lisa Ruby.  I have not had a chance to review the book but from other reviews it is seen as another book exposing the false teachings of the "Left Behind" series books that are misleading many sincere people into a false feeling of  "safety" along with a few other false doctrines concerning the "end times", "end days", "last days", or the "tribulation days".  This site is worth a look.

www.midnightcall.com A staunch teaching organization of the rapture.  They have a lot of truth and a lot to agree with but be aware, they have thrown the whole lot into the promotion of the false doctrine of the ratpture and ot the "imminent" return. 

www.ag.org  Assemblies of God, official web site and teachers for the "rapture" doctrine, not to be confused with the "resurrection" doctrine the Apostles of the Christ taught.