Additional Accent and Dialect Resources
There are many excellent resources and practitioners for accent and dialect work. Below are links to some that I have found useful. This list is not exhaustive.
How to do Accents - the Sharpe/Haydn Method
The Accent Handbook by Jessica Hammett and Lottie Williams-Burrell
J.C. Wells’ Accents of English series
Paul Meier and the International Dialects of English Archive
Beth McGuire’s African Accents: a workbook for actors