Keith Mathison from Ligonier Ministries has recommended 13 books on the doctrine of God. Check out the list HERE.
I would add to that excellent list a few titles that are a bit more accessable to the lay person:
Knowing God by J.I. Packer
Behold Your God by Donald MacLeod
The Message of the Living God by Peter Lewis
A Heart for God by Sinclair Ferguson
The Pleasures of God by John Piper