The following resources are very helpful for digging into God’s word:

StudyLight has everything you can possibly need: http://www.studylight.org/

E-Sword is great resource for downloading stuff: http://www.e-sword.net/index.html

Blue Letter Bible is a pretty good resource as well: http://www.blueletterbible.org/index.html

Crosswalk offers a wide variety of useful tools: http://www.crosswalk.com/