Great news for Mac geeks all around: today is Upgrade Day. OS X Mountain Lion, the next major version of Apple’s desktop operating system (previously known as Mac OS X), is due out today.

If you’re planning to do a clean install, Matt Gemmell has rescued this fantastic article that will help you get your Mac ready for the upgrade:

This checklist is for situations where you want to start fresh with a clean installation of OS X and just your essential apps and files, which can provide a general speed boost and may also be a useful preparation for a major new version of OS X.

This may be a good way to kill some time while we wait for John Siracusa’s traditionally epic review of the new OS, which should also be out later today.

Enjoy, my friends, this day comes by just once a year.