Over on my personal blog I’ve documented How I write The Screencasting Handbook. I want to keep the process open so other people can replicate my process and improve upon it.
Amongst other things I talk about how I decided on the topics that needed covering, the infrastructure behind the site and what I might do for the second edition.
To improve your screencasting knowledge you must read The Screencasting Handbook. The author (Ian Ozsvald) also blogs.