There's a very fine summary of the economics of selling your ebook on the Kindle, found on Eli James' blog Novelr. Most books of genre fiction are priced at between $2.99 and $4.99. But if the books are priced at $.99 the author gets only 35%; Amazon figuring it needs a minimum of $.35 per book. Top selling authors can move 10,000 copies per month.
Novelr has a good roundup of the various ebook formats for independents, but it is a bit dated now (2009). To turn your Word document into an ePub format and then onto the Kindle, go to another blogger, Linda Nagata who has an extremely detailed tutorial on how-to. (I have not tried it yet.) More how-to info here. If you want to hire a pro to Kindlize your book quickly, you can try Rob Siders, for example. (I have not used him.)
Does anyone have a bettertutorial for DIY going from Word to Kindle?