Idea of writing a book/handbook...How do I start the process?

just write dude. i don't know what you're complete situation is, because i'm too lazy to read it, but i'm a self-published author working on my 4th book, and i've never been able to find a specific way to write. you just write about what you're pionate for and when you feel like it. once you get started, it should be easy to finish-watch it for writer's block if you over do it though.