If you are interested in learning the IPA phonetic transcription system and understanding how it is used to transcribe English, I would recommend these. They show the symbols and have sound files.
- http://www.paulmeier.com/ipa/diphthongs.html (British & American)
- http://www.antimoon.com/how/pronunc-soundsipa.htm
- http://faculty.washington.edu/dillon/PhonResources/newstart.html
- http://accent.gmu.edu/ – Same sentence in multiple accents
For Australian/New Zealand (no sound files, but excellent description)
http://www.ling.mq.edu.au/speech/phonetics/phonetics/ausenglish/auseng_vowels.html