Much of what the Dalai Lama has written provides wonderful guidelines for living and for being a human being, without tying into any particular religion (even his own). His new book Beyond Religion: Ethics for a Whole World proposes a secular ethics which aims to go beyond religion (or be independent of it). I also found his The Art of Happiness very compelling. In this book, he cites compassion as the most important value.
A virtue that quite naturally follows from compassion is Tolerancetolerance is another important virtue, which incidentally forms one of the founding pillars of Dutch society. This follows on quite naturally from compassion.