Hey Fam:
I've bought a lot of books over the last year or so, and I haven't gotten to read many of them like I'd like to. But, there is one in particular that I am enjoying greatly.
Our brother, Redeemed, mentioned this book on another forum, I believe. It's called "The Way of Holiness: A Study in Christian Growth" by Kenneth Prior.
It's only 166 pages and while it's packed with much weightiness, the author's literary style is easier to read than a lot of books like it.
I bought mine from Reformation Heritage online. I only paid $2.50 for my copy, which was barely used.