Forums:
MG Experience – Likely the largest MG web site in the universe. This is the place to go with your questions. The site also has an impressive online library and buy and sell section.
British Car Forum – While not as large a community as the forum above this forum has lots of information and good advice. Join both!
Manuals:
MGB Workshop Manual – A 417 page factory workshop manual with a great section on service tools.
MGB Manual in French – Do you speak French? This is for you.
Tuning your MBG – Stephen Strange has written 1,408 pages of amazing information to help you get the most out of you MGB. This is worth a read!
MGB Wiring Diagrams from Advance Auto-Wire – Every wiring diagram you could possibly require for your MG.
Engine:
Performance Tuning the B Series Engines – Very intensive write up about tuning your MG engine, Stephen Strange knows his stuff!
Engines for MG’s, Their story after 1935 by Neil Cairns
Tuning SU Carburetters including Full Needle Charts
Books:
Tuning BMC Sports Cars by Mike Garton
MGB Tourer and GT Special Tuning (1963-1967 models) – from British Leyland Special Tuning Department
Competition Preparation Manual, MGB – J. W. Huffaker, Huffaker Engineering Co.
Catalogs:
Anglo Parts – This European based company has a nicely illustrated catalog with lots of tips on how to improve your MGB
Web Sites:
EarlyMGB.com – An excellent resource for those restoring early MGB’s to their original specifications.