Scoutmaster Clarke Green, from Scoutmastercg.com, sent me the link to this gem. Scouting.org is a wonderful site with tons of great material that nobody ever sees and this is one of the better documents. I’ve yet to figure out how to successfully navigate it and my best way to find useful materials is either to stumble blindly across them from unrelated google searches or by being directed there from other sources. (Usually this method results in broken links!)
Anyhow…
The Advancement Educational Presentations page on Scouting.org has a number of resources and videos that efficiently and effectively reviews and teaches many of the areas covered in the Guide to Advancement, giving some depth and insight into the topics.
Of particular interest to me is The Essentials to Merit Badge Counseling Powerpoint, with the Instructor’s Notes. It’s a great resource for a volunteer that has been recruited to serve as a Merit Badge Counselor and wants an understanding of the program and how it fits in with the Scouting Program. While it may be a bit long to expect most casual volunteers to look through themselves, if your unit provides formal training for Merit Badge Counselors, I think this is heads and shoulder above what I’ve used in the past.(18-125) This, paired with the Merit Badge Blue Card Infographic really gives a troop some perspective that might be missing when trying to get a volunteer to navigate the Guide to Advancement as your only resource.
None of this information supercedes or replaces the information found in the often updated Guide to Advancement, so you still need to keep abreast of that, but this stuff sure does a great job of supplementing!
The link once again: The Essentials to Merit Badge Counseling
An Hour a Week.... left over after Scouting 
Even more succinctly: http://www.scoutmastercg.com/scouting-advancement-educational-presentations/