A friend recommended to me Mark Kingwell's 1998 book In Pursuit of Happiness. This isn't yet another self-help pep-talk quickie; Kingwell is a professor of philosophy at the University of Toronto and the book is a readable overview of what philosophers, thinkers, novelists, and science have had to say about happiness (the subtitle is "Better Living from Plato to Prozac"). Moreover, the man can write. He's wry, concise, and witty.
Short version: from several millennia of writings on the subject of human happiness, Kingwell distills four basic approaches:
1) Lower your expectations. This is the strategy of, for instance, the Stoics: If you don't expect anything and don't desire much outside of yourself, you probably won't be disappointed.
2) Take the long-view. Whatever you're going through now may feel awful, but in the long run it (pick one or more) a) will teach you valuable life lessons, b) will not seem so cataclysmic in the overall arc of your entire life, c) won't matter after you're dead, d) will all be accounted for in the next life. This is the "This, too, shall pass" crowd, plus many religions, plus deep-dyed cynics (a set of uneasy bedfellows, one would think).
3) Look at the half-full glass. Count your blessings, accentuate the positive, you are what you think, reality is malleable according to how you view it. This covers everybody from Dr. Phil to the Eastern mystics.
4) Redefine happiness. This is the deepest choice, advising concentration not on feelings but on rational satisfaction with the course of a life lived within a larger context of ethics, community, and personal responsibility, however constrained by circumstance. One must be able to say, I choose this and I accept that I have chosen it. Aristotle and a bunch of followers.
I'm being a little flippant here -- but so is Kingwell in his book. At any rate, it's a thought-provoking, accessible book, and I recommend it to anyone interested in such matters.
Also connected with books: Webperson extraordinaire, Sharon Keir, has updated my website and put up the first two chapters of my July biothriller from Tachyon Press, Dogs, should anybody care to read them.