Special information for Merit Badge Counselors:
Youth Protection Training Online in MyScouting.org
BSA Adult Application (PDF for 3 part carbon-less form. Use the carbonless form if available)
Merit Badge Counselor Application
BSA Resources for Merit Badge Counselors
The best (and only official) source of requirements and instructional material for merit badges are the current version of the merit badge pamphlets, available at the Scout Store or from BSA National Supply. Here is a great unofficial sources of requirements: