This site has animations with sound to help learners with sounds (diphthongs), stress (word and sentence stress), and intonation (rising and falling intonation). It also has phonemic charts for English vowels and consonants - click on the symbol to hear the sound.
Useful for even beginning learners, and a good resource for checking general rules (e.g., word stress) and the phonemic inventory of English. Teacher can supplement these basic rules with additional examples and more detailed rules for pronunciation.
Via Renee Maufroid, Juergen Wagner, Teresa MacKinnon, Shona Whyte