For me, reading one of those Bible-in-a-Year books was quite frustrating. Ironically, Survey of the OT, at 300 pages, is far less overwhelming. If I quit trying to rush it, I will really understand by the time I finish. Extremely user-friendly, includes outlines, maps, chronologies. For normal folks, not scholars, and yet it seems scholarly. The Old Testament is well over half the Bible!
I borrowed this book from a neighbor and now I don't want to return it! I think I'll get my own copy. This book really boils the vastness of the Old Testament down to the nuts and bolts. Just read a chapter and then go to the Bible book it discussed and read it. Your understanding will be so much clearer.