If you're anything like me, you might have days/weeks where you don't have quite enough time to browse all of the writing blogs/articles you'd like to. I thought I'd post a link to each of the alerts listed in 2012, in case you're looking for your agent match.
For your convenience, I've put "*" next to agents who accept Young Adult manuscripts and "**" next to those who also take Middle Grade manuscripts. Otherwise, assume that the agent handles adult fiction and non-fiction (keeping in mind that tastes can change, and that they may open to other age groups/genres at some point in their careers).
At the bottom, there's a link that includes information from other years as well.
New Literary Agent Alert: Brenna Barr of Dystel & Goderich Literary Management
New Literary Agent Alert: Linda Glaz of Hartline Literary Agency
Here's the Writer's Digest post that contains all of the links, going back to 2007: New Agent/Agency Alerts