I've written several posts about the problems with self-publishing and the problems with places that say they edit your work and publish it as long as you pay them ooodles of money, but actually only copyedit your work and fall down on the marketing side of the business. (Vanity presses -- avoid them. Money should flow to the author, not away from.)
But what about places that ask you to do stuff for them for free?
Stephen Silver says, "Say NO to Free!"
Often,you'll discover that they expect you give up the rights to anything you post or send to them.
He's talking about artists and art, but there are "free" places for writers that do the very same thing.
What about doing talks or school visits for free? Here's info about that, too.