My dad has a friend who's planning on self-publishing her first book soon. My dad forwarded the friend's email to me, asking for any advice, and I spent a few minutes thinking about it and wrote the following:
Self-Publishing Advice from M.F. Soriano
1. The place where I've learned the most about self-publishing--what works and what doesn't--is the Writer's Cafe section of the kboards.com forum. I recommend joining the site and reading extensively.
2. Sales mean most, and promotional efforts are most effective, during the book's first week live (ready for purchase). This is when Amazon is establishing it's ranking of the book, and it's easier to start with a good rating than to sell poorly at the start and then try to crawl back from the bottom of the Amazon ranking list. With that said, I recommend setting up certain promotions in advance. Two sites that promote books and will reserve a spot in advance (before the book is online and can be linked to) are kindlenationdaily.com and bargainbooksy.com
3. In general, be conservative with money and effort. There are limitless amounts of things you can do, and money you can spend, and the vast majority of it will have NO positive effect. Most self-published books sell less than 100 copies. If a book does better than that, and goes on to continue selling on its own, it pretty much comes down to positive word-of-mouth. So put some promotion in at the start to try to establish some visibility and give the book a chance to start selling by word of mouth, but don't keep dumping money and time and energy into it after that. You're better off putting that time and energy into writing another book.
I'd say a budget of less than $1000 for a book--70% for cover design/formatting for print and ebook versions, and 30% for that initial launch promotion--is all you really need. My most successful book was launched for $200 ($30 for cover and $170 for promotion). Spend more than that and you're probably not going to get a return on it, and lots of the more expensive services--like hiring someone to do web-design/public-relations/promotion--are VERY unlikely to ever produce sales in a way that will justify their costs. The book must have the ability to sell itself--throwing money at it will not change that.
A pretty good book for learning the basics of self-publishing in the digital book world is: Let's Get Digital by David Gaughran