Copied directly from this link:
Here are links to Merit Badge resource pages and worksheets along with the requirement Revision Dates. Make sure the Merit Badge book you are using is not out of date (older than the revision date). Rank workbooks are also listed.
Merit Badge Workbooks (worksheets) are not required but are tools that can help Scouts organize notes, listen actively, and document their work. See Merit Badges for more details on earning a Merit Badge. Workbooks allow Merit Badge Counselors to offer group instruction but still "...test the Scout individually."BSA Click a merit badge below for the current requirements. "You should read the merit badge pamphlet on the subject."BSA Merit badge pamphlets (books) are available at your local Scout Shop or online at ScoutStuff.org.
Here is a table of T105 Merit Badge Counselors with the merit badges they teach.
And finally, here is the BSA list of merit badges with their requirements.