I just got back from Scrum Master training, and I must say I was pleasantly surprised by the two day class. So I'm taking a break from the Unit Testing posts to do a quickie on the class.
I attended a class by Michael Vizdos, one of 30 Scrum Trainers in the world. Michael did an excellent job of answering our real-world questions about integrating Scrum/Agile into our various organizations.
The class was a mix of individuals brand new to Agile and a couple of us that are fairly experienced with Agile. I have been doing Agile for a long time when my customers allow (and work in Agile concepts when they don't), and definitely had some strong opinions about the "real world". The individuals without the experience brought an unjaded view point, and the levels blended well.
Michael did a great job of helping us work through our collective issues and see what Scrum (or parts of Scrum) could do to help us. He also wasn't afraid to say a couple of times "Scrum won't work there".
So, my recommendations? Have some experience with an Agile methodology prior to going to the class. The more the better. However, if that's not practical, at least read some info on Agile/XP/Scrum prior to going. Either way, you'll get good information.