Pen and Paper
The most necessary tool in Bible study besides the Bible is paper to record your questions and insights. Not only is this necessary if you do not have a photographic memory, but also to work out your own thoughts. Writing helps one to think. The mind has the unpleasant ability to be easily sidetracked. Writing helps to focus your attention and follow a particular line of thought. This is extremely necessary when studying the Bible.
These are just some of the major tools to aid you in your quest to understand what God has written. The more you study and learn, the more you will learn to study. Do not be afraid or intimidated by the immensity of the Bible. It is shallow enough for a child to wade and deep enough for an elephant to swim. Come on in, the water is fine!