Clive Shepherd, an education consultant in the UK, has written a very useful post about the processes involved in self-publishing in paperback via Lulu, and electronically in the formats required by the iBook, Kindle and Sony Reader.
What I especially like about this article is that it deals with the practicalities involved – including the rather daunting(in my opinion) formatting conditions imposed by Smashwords. The process is probably fine when you have started to address it in earnest, but if your book has footnotes and tables you will need to do some editing before submitting it to Smashwords. (No doubt worth doing though, because Smashwords will convert the manuscript to several e-formats, and by all accounts is a huge marketplace.)
There’s also a useful comment by John Betcher, whose self-publishing tips I wrote about yesterday.