This collaborative project led by the University of Iowa is an example of the Web incredible potential. It is a tool for students (and also professionals) of Phonetics, Linguistics and foreign languages. The site contains animated libraries of the phonetic sounds of English. You can see an animated articulatory diagram, a step-by-step description and a video of the sound spoken in context. Who has not yet faced difficulties in producing English sounds? This is the right place to solve that kind of problem. However, bear in mind this is an American tool, so the results you will get are for American English.