If you're running Moodle 2.1.x and wish to upgrade to the latest new-fangled Moodle 2.2, then here's an EXCELLENT resource, generously littered with clear screenshots.
Here are two other great and related blog posts by Guido and Miguel .
Source: http://moodle.org/stats/ as of 11th Decembr 2011.
It'll be at least June 2012 before you can expect the release of Moodle 2.3. So until then, here's to using moodle 2.2.