IDEA: The International Dialects of English Archive
Founded by dialect coach Paul Meier at the University of Kansas, IDEA is a wonderful on-line archive of English language dialects and foreign-language accents, producing different kinds of speech.  Nearly 1000 freely downloadable recordings of native speakers.

Sounds Familiar? Accents and Dialects of the UK
The British Library provides this great clickable map of the UK with new and old recordings that reflect regional, social and ethnic variation.

The Dialect Resource
Dialect coach Gillian Lane-Plescia makes a wide range of dialect/accent recordings commercially available, as CDs and downloads.

Accents of English
Wells, J. C. (1982).  Accents of English (Three volumes + recording).  Cambridge University Press.
For those with phonetic training, this is a classic text by my own teacher at UCL, Professor John Wells.

Audio-visual IPA charts
For those who have some familiarity with phonetic symbols, dialect coach Paul Meier has provided a superb resource with complete audio-visual IPA charts – just click on each symbol to hear Paul producing the appropriate sound.  (Flash animation by Eric Armstrong of York University, Toronto)

Vowel chart
English accents differ mainly in their vowels.  For those new to phonetics, this very compact introduction to the "vowel space" is provided by top Hollywood dialect coach Joel Goldes.

A Course in Phonetics
Easily the best-known introductory textbook on phonetics, by the late, great Peter Ladefoged, Professor of Phonetics at UCLA during my own time there.

Longman Pronunciation Dictionary
This well-known specialist pronunciation dictionary is by my own teacher Professor John Wells.  Includes the results of American and British pronunciation polls, and a CD-ROM with interactive resources featuring Prof. Wells.

Oxford Advanced Learner's Dictionary
The biggest selling dictionary for learners of English, with more than 30 million sold worldwide.  The Pronunciation Editor is Michael Ashby – another of my teachers!  I myself was involved in the extensive CD-ROM recordings.

UCL Summer Course in English Phonetics
Two-week summer course at the world's leading university department for English Phonetics, focusing on the difficulties of English pronunciation for learners of EFL.  I will be returning to teach there in 2009.