Having only made the leap from svn to git a month ago for my private repos, this is exactly the kind of guide I've been missing. Everything makes a little more sense now, thanks!
"A git repository can be a completely local undertaking. The whole repository content is stored in a folder named .git in the root of the project folder"
This is one of my favourite things about Git. These days I create local git repos for practically everything I do and basically use them as persistent, super-flexible "undo".
I'm waiting for someone to write a nice text editor which completely integrates this process; I'd be a customer for sure.