An excellent post here by Jim Hines – it helps debunk some of the more common myths about self-publishing that has come out over the years.
I do think that there’s definitely a spot for self-pubbing – poetry, nonfiction and so forth, where you know the sales aren’t going to be great, depending on how your contacts and connections are.
It’s often heartbreaking to see someone boldly rush into self-pubbing without realising the amount of hard work it takes to be successful – or worse, think that they’re self-publishing when they’re just subletting their work out to a small vanity press. If you selfpub, go the entire way – buy the ISBN and arrange for the printing. You’ll make and save more money in the long run since you’re the boss… but you’ll do a lot of solo promotion and it’s a hard road to walk. If you do, get the books out there on how to do it right.