The main resources for information on Scouts BSA Advancement are:
The information in the latest editions of these two documents are the official positions of the Boy Scouts of America and supersede information in previous versions or in other documents. Each unit should obtain the current copy of each of these documents. No council, district, unit, or individual has the authority to add to or subtract from any advancement requirement.
The Guide to Advancement, issued in early October 2011, replaces the Advancement Committee Policies and Procedures and contains some significant changes and clarifies a number of advancement related issues. Every Troop should have at least one copy for reference.
Additional information is contained in:
The Boy Scout National Council website includes the latest rank requirements, requirements for all merit badges, and additional advancement and recognition information.
There are numerous other online resources for advancement. The quality and accuracy of these sites vary. While it may be worthwhile to check out these resources, the BSA documents are the official resources. With some of the changes in the Guide to Advancement, many of these sites will be out of date, so be careful in using them.