Calvin's Commentaries - http://www.ccel.org/ccel/calvin/commentaries.i.html

Matthew Henry's Commentary on the Whole Bible - http://www.blueletterbible.org/commentaries/comm_author.cfm?AuthorID=4

Monergism - http://www.monergism.com

E-Sword (free Bible program) - http://www.e-sword.net