At my church we're going through a book called Sacred Bond in our adult Sunday school class. It's a brief introduction to covenant theology, and a very helpful resource thus for. It is a very accessible book for the person who is new to covenant theology, or the uninitiated layperson. Concepts are simple and well explained, and it is quite pleasant to read. I read a lot of theology for fun, but I find myself really enjoying getting back to the basics. This was very true when we went through the chapter on the Covenant of Grace.