What's an e-book? (and other fan questions)

I've been asked several questions about e-books since the sale of Harvest Moon. While I don't mind repeating myself (after all, I worked for a cell phone call centre for years), I decided that a blog post might be the best method.

So, what's this e-book thing?

An e-book is a digital copy of a novel. It's in various formats, from things called "epub" (meaning it's read on Sony e-Readers and such) to "pdf" (most people know what those are; you usually open them using Adobe Acrobat).

How do you...