Commentaries
Commentaries should be the last resource to use. Too often we let men tell us what the Bible says instead of studying and laboring to understand its meaning. I use commentaries to help me after I have researched the text and still have no clue, or once coming to a conclusion on the text I use commentaries to compare my answer.
There are so many commentaries in one volume and multi-volumes that it is hard just to mention one. I prefer Barnes Notes on the Old and New Testaments and Matthew Henry.
Computer Software
Today, Bible study is so much easier thanks to computers. Bible programs can have all of these resources and more at your fingertips. My preferred program is the Online Bible. It is a wonderful tool and its downloadable for free. The web address is www.onlinebible.net
There are several websites that also have many of these bible study tools. A list of a few are: