The Scrum Master certification is one that demonstrates knowledge of the process, roles and responsibilities, and the lexicon of the practice. It does not mean you are a "good" Scrum Master, or that you can (or want to) be one. This is why the certification is applicable not only to those that may perform the role, but for everyone on the team so they know what is expected of/from them.
Our goal - to get you knowledge and skills that can help you forward your career, at a reasonable cost, both in time and money.
If you have been a Project Manager for a while, a weeks worth of self-study (an hour a day or so) to add the terminology and Scrum framework to your knowledge base is probably all you need to pass the exam. It's not "hard", but if you haven't had some experience with project communication, requirements estimating, etc., then you will just need to study a little more. Read up and take the exam from the ISI!
By the way, we are not affiliated with the Scrum Alliance for the Scrum Master certification. We are affiliated with the International Scrum Institute based in Zurich, Switzerland, which awards the Scrum Master Accredited Certification upon successful completion of their on-line test (the cost of which is included in our PMP and ACP courses). As of March, 2012, they have over 347,000 certificants on file in 143 countries.
What's the difference? Having taken both tests, I feel the ISI exam is more Project Management aligned, and the Alliance test more developer/programmer aligned. The difference is very subtle, and probably not recognizable by most [which could also mean I'm imagining it! :o) ].
The ISI (click here) provides FREE training tutorials on their site, and then there is YouTube! There are litterally dozens of good videos on Scrum on YouTube. Check out Scrum 101 (4 parts) and others. Read over the ISI tutorial, watch a few videos, and take the exam. It's that simple.