I understand your dilemma. It is really helpful to have an overview of the Bible in your mind before you start reading it in detail. This helps to put what you are reading into the context of the "big picture". With this "big picture" in mind, you will find the that the scriptures will open up to you in ways you never thought possible before.
For example, do you know why the very first verse of the New Testament refers you back to the life of David and Abraham in the Old Testament? Figuring out why this is so will put the Bible and the Gospel message in a whole new light for you! Did you know that the New Testament has literally thousands of references back to the Old Testament? Having a good overview of the whole Bible will really be useful in understanding the message God is giving us in His word.
A really helpful discipline is to read the Bible prayerfully and systematically every day. Here is a link to a website which will help you do this and also provide useful comments on each day's readings. If you follow this system, you will have read the Old Testament once and the New Testament twice in the course of a year. Here is the link: www.dailyreadings.org.uk
I hope you have found this helpful.