I have started to read John Piper's book, When I Don't Desire God: How to Fight for Joy (2004). It was first recommended in a talk given by Justin Moffatt for its chapter on memorising parts of the Bible. However, as I have written earlier, I may find this book useful in a broader sense.
I also came across this excellent resource by Greg Koukl on reading effectively. He breaks down the task of reading a book into four stages (if you get past stage one), the first of which is Overview. In Overview mode he suggests skimming the entire book at a rate of 2-3 seconds per page. I tried this on When I Don't Desire God and found that Piper makes many references to the works of C.S. Lewis. (This shouldn't surprise Lewis fans: his autobiography was entitled Surprised by Joy.) Every couple of pages something of interest jumped out at me. So I have decided it is time to move to stage two: Preview.