Here are some powerful Bible study links that I use regularly. Perhaps they could be of use to you, too.
Blue Letter Bible. Commentaries and Hebrew/Greek lexicons make this a daily favorite of mine
Study Light. Excellent place to find good word studies:
Christians Unite. You'll find devotionals, study guides and even biographies on this fine site:
God and Science. Contains and excellent section on the prophecies of Christ:
William Lane Craig Debates. This is powerful stuff. Dr. Craig takes on all non-Christian comers in a stand-up debate that will amaze you on the truths of the Bible:
Institute of Creation Research. Great site for learning scientific truth and God's Word:
There are numerous more fine places to study. I will be posting them in future weeks. I hope these help you as you lead your Bible studies or prayer groups.