A National Map of the Regional Dialects of American English
PhillyTawk: Overview of mid-Atlantic English, Part 1 (YouTube)
PhillyTawk: Overview of mid-Atlantic English, Part 3 (YouTube)
Linguistics Society of America (LSA) style sheet (PDF)
Word frequency data from the American National Corpus
Praat (acoustic analysis software)
Full International Phonetic Alphabet (IPA) chart
IDEA (International Dialects of English Archive)
Web CELEX (searchable lexical database)