This may be personal to me, but I tend to fear that books on this topic will be a bit drippy, nebulously positive feelgood items. Happily, Sharon Salzberg is a true teacher in the Theravadan tradition and helps me move towards lovingkindness as i think it was meant. As she presents it, lovingkindness is clarity about the flaws in the world, ourselves, other people. Lovingkindness is a compassionate non-denial of what things are like. Oddly, lovingkindness turns out to be the antidote to fear. It opens us up to the world, rather than trying to drape existence in pink positive soft-focus light. Open, loving, fearless, accurate, non-narrow, non-petty; we've got a lot to thank the Buddha for, and this is a truly wonderful exposition by Sharon Salzberg. She provides great stories, deep understanding and, critically, the kind of precise, technical meditation tips that are the blessing of the Theravadan tradition. There are a lot of solid, traditional metta practices straight from the canon summarised in here. A book that I will be mining for years.