If you write MG, you don't want to miss the Middle-Grade Madness with Agent Terie Wolf and Author Sharon Mayhew. Check out Sharon's blog for details: http://skmayhew.blogspot.com/2014/03/mid-grade-madness-contest-detail-with.html (Terrie is hosting/hosted a Q&A session today. If you missed it, it MIGHT be available afterward. IDK, yet. Try this link: https://plus.google.com/events/c387bv0v2efschvfi13cv4mgebg Maybe it will be listed later?)
Also, you can view a boat-load of calls for all genres in Tumblr. Follow the #mswl ("manuscript wish list" from agents and editors) When we can, we track down the contact info for each call and post it here. More coming soon.