We've known about iTunes Match for a while, but it just went live today. The $25/year music service promises to not only store your iTunes purchases in the cloud, but to back up your non-iTunes tracks as well. So how does it work exactly?

The first thing you need to do is download and install iTunes 10.5.1, which you can find here. If you need further explanation on how to install iTunes, give up now. As for the rest, well, walk with me.