Since Apple just recently launched their iTunes Match service for users in the United States, you might be curious how to subscribe? Luckily, subscribing to iTunes Match is just about as easy as making an App Store or iTunes music purchase. Once you're all paid up -- it's $24.99 a year -- and set up, you'll be able to access an online version of your iTunes library via iCloud from devices such as your iPhone, iPad, iPod touch, and AppleTV without physically having a computer to stream from.
First launch iTunes on your computer and make sure you are running iTunes version 10.5.1 or higher.
Next you should see an iTunes Match section under Store in the left hand pane. Select it. (If you don't see this, you can alternately go to the iTunes Store homepage and select iTunes Match from the Quick Links section on the right. This option was missing for me at first and then magically appeared... weird.)
Next you'll need to click Subscribe to iTunes Match for $24.99. You'll be asked to input your iTunes password. (You'll only see the not taking subscriptions message when the servers are slammed. If you get this, just try subscribing later.)
Next click iTunes Match in the sidebar just like you did to purchase it and you should now see an option to add your computer. Do so by clicking the Add this Computer button.
iTunes will begin Step 1: Gathering information about your iTunes library. In this step Apple scans all your songs to see what's in your library.
In Step 2: Matching your music to songs in the iTunes Store, Apple compares your library to the massive iTunes Catalog. Anything that already exists in the iTunes Catalog is immediately made available to you in standard iTunes format -- 256Kbps AAC with metadata and album art.
Step 3: Uploading artwork and remaining songs takes any other music in your library -- anything Apple couldn't match with the iTunes Catalog -- and uploads it to Apple's servers so it will still be available to you from the cloud (albeit in its original format, if that format was worse than iTunes standard.)
Troubleshooting iTunes Match
A few things you'll want to pay special attention to:
iTunes Match can only handle 25,000 songs. If your library is bigger than that, iTunes will refuse to match it. About all you can do right now is create a new iTunes library on the same computer with a subset of your songs -- no more than 25,000 -- and use that library to set up iTunes Match. (Just make sure you don't copy your music into new folders, leave it in its existing folders or you'll waste a lot of disk space.)
iTunes Match isn't currently doing a great job actually matching a lot of songs. It could be an issue with metadata, if the song information is really different between the iTunes Catalog copy and your local copy. You could try updating the metadata on your local copies before going through iTunes Match, but it can take a lot of time and results may still vary. (Anything iTunes doesn't match gets uploaded to Apple's servers, so you still have access to it, but in its original form, not the iTunes Catalog copy in 256Kbps AAC with "official" metadata)
That's it! iTunes Match should be happily processing, matching, and uploading your library. In the meantime, let us know how the setup went for you, and if you have any issues, jump into our iTunes Match Forum and get some help!