Pronunciation differences US/UK Englishes
Sounds familiar? Accents and dialects of the UK (British Library) Link sent by Gonzalo (Y5, 2007-08)
Practice pronunciation with Merriam-Webster's (US American English)

How do you pronounce ... ? Learning Phonetics
A chart with all the sounds and their transcription: vowels and consonants
Check out Merriam-Webster On-line (English-English). Click on the loudspeaker and you'll listen to the pronunciation of the word (US American accent).
"Ship or sheep?" Can you hear the difference between the different vowels? Practice Listening and Repeating at this website with minimal pairs and pictures of the words. Click on the numbers or the pairs of words here and you'll get to a page with extensive oral practice on the vowels in that pair! Here's some info on how to use that website .
Pronunciation of the -ed ending - Explanations and exercises by your teacher, including 2 pages of useful sentences with their audio
Pronunciation of the -ed ending 02 - more stuff plus links to on-line exercises
BBC: Pronunciation Tips Good exercises you can download to learn to listen.
Phonetics in the Classroom: Phonetics 01 (1 page)
AN AMAZING EXTERNAL LINK: Learn how sounds sound!, their transcription, and more things! Listen while learning phonemic transcription! (you need Flash)
Vowels Diphthongs Consonants More consonants Pronunciation - exercise Look at the picture: you will use the two rows of labels to click on them and get what you want. Click on the English Library here and learn it all about the phonemic system!

Pronunciation Poem! (from British Council )