June 1, 2010
From the Quick Links section on the upper right of the iTunes main page, the My Alerts link takes you to a page where you can choose to see what's coming and what's recently arrived from artists whose content you've downloaded from the store, and to receive email alerts when new content from them appears. If you have Genius turned on you'll also see an option to have iTunes look at all the content in your library no matter where it's from to determine what to display. When you choose an option it'll be in effect the next time you click My Alerts. Don't be afraid to experiment. You can turn options off immediately if you don't like the results, or at any point in the future if your desires change.
There's another route to requesting email alerts about artists for music fans. When you click an artist's name in the iTunes Store, whether from search results or on an album page, you're taken to what amounts to a clickable index of all of that artist's albums and songs in the Store, plus a set of Artist Quick Links on the upper right. Click Alert Me and you can choose to add the artist to an email alert list of specific artists. To remove artists from the list after you've added them, use the Manage My Alerts button accessible via My Alerts on the iTunes main page and additionally from any alert emails you receive.