I have just finished reading this really good book on discernment by David Lonsdale. As a spiritual director I felt like I should know more about discernment. I have now read this book twice. It offers a really good introduction to discernment, both on a daily basis and for the big stuff. He basis this way of making choices on a profound sense of our being loved unconditionally by God, a sense that comes out of regular prayer and reading and reflecting on the scriptures. He explores how good discernment holds together both the affective, in particular whether we are being led to God or away from God, and our head. He also explores the obstacles to good discernment.
This is a really easy to read and informative book which I recommend to any interested in this basic Christian discipline