How-to: htaccess and SSL redirects

So, you've got a site that you want to require SSL on, but not for certain pages? I couldn't seem to make sense of most of the documentation out there on Apache's mod_rewrite module, so after 3 days I finally came up with the rules that work for this task. I figured I'd put them up here to help anybody else who runs into a similar requirement, and so that I have it sitting somewhere that I won't forget about it!

Also, if you happen to have certain directories that you want to be available via standard http and not https, place this into an .htaccess in the appropriate directory:

I'm sure there's a better way of doing this in-line with the root .htaccess file, but I gave up trying to parse the mod_rewrite documentation. It's like trying to find the meaning of life in an Calc 5 book.