I've recently needed to setup an extranet for several websites and began researching. There are several helpful articles on the topic. I found bolaky.net and blog.wojciech.org as well as using Sitecore's Security API and Security Administrator cookbooks. Although there was enough information to get me started, what I found was disjointed and there were a few specifics that weren't detailed. After some testing I was able to create a functioning extranet and in an effort to create a more comprehensive article I have detailed my results.
1. Create Extranet Sublayouts
The first thing you'll want to