Depending on your budget, I'm a big fan of a commercial tool called PrinceXML, which consumes [html|xml]+css and produces PDF. All of the big self publishers a

Depending on your budget, I'm a big fan of a commercial tool called PrinceXML, which consumes [html|xml]+css and produces PDF. All of the big self publishers accept PDF as one of their printing targets. Of course, this means you're writing a book in HTML, which is either a huge win or an enormous loss, depending on who you are. But, given that it's HN, I figure there's a half decent chance this is right for you. There's a free version you can try it out with; the commercial version is around five hundred bucks. In my opinion, totally worth it. YMMV.