These I buy second hand from Amazon - almost always available, usually for 1p each! I believe that it is now out of print, so not available new. New Christians are often not ready for deep scholarship, or for the heavier Bible commentaries like Matthew Henry - but need some introduction to be able to really make sense of many of the denser books of the Bible.
This commentary is easily the best I have found for this purpose; it is readable, and it puts each book in context in a way that is easily understandable and uncomplicated.
Highly recommended for those who want greater understanding of the Bible, without the kind of heavy scholarship which makes many much larger and more detailed commentaries difficult to absorb, and potentially intimidating even to pick up and open!
I keep several copies of William Neil's Bible Commentary in reserve, to give away as needed.