Stephen Charnock's Discourses Upon the Existence and Attributes of God is a classic, but is over 500 pages. Daniel Chamberlin has done the church a service by summarizing the essential thoughts of Charnock on the doctrine of God for the 21st Century reader.
This is a great tool for groups to work through together, as each chapter is nicely divided up into bit size portions.Jeff has highly recommended it to me, and I look forward to reading it myself. Please let us know what you think here at the Reformed Baptist Blog after you've had a chance to read it yourselves. If you are interested in digging deeper into Charnock's work, you can get the free eBook here. I think you will quickly appreciate why an introductory, summary work such as A Portrait of God can be so helpful, especially if you are trying to acquaint others with such theology.