Peter Ladefoged from the University of California prepared pronunciations of all of the vowel and consonant symbols on the basic International Phonetic Association chart. His work has the sounds of vowels and consonants, vowel contrasts, intonation examples and many other useful phonetic resources.
Spoken English Online offers a list of popular idioms used in the English language. It also contains a list of links to some other helpful websites that provide idiom usages and meanings. Another great idiom resource for American phrases is English Daily. It provides a context in which each idiom can be used, to further help explain its meaning.
English Pond lists a range of important phrases and expressions that are used in normal daily conversation. It provides written text examples as well as an mp3 audio which you can listen to, to hear how the sentences should be used.
A resource developed by the University of Edinburgh contains a comprehensive list of English accents from around the world. It allows you to hear and compare pronunciation of the same words from different regions. The University of Washington's website has a page showing the variations of vowel sounds of American English and British English. It contrasts both sets of vowels in a quadrilateral that indicates where the tongue should be positioned to articulate the correct sound.
English Meeting is a website with links to a whole range of online ESL instructors that provide on-demand audio and visual lessons. There are pronunciation, vocabulary, grammar and quiz resources catering from beginner to advanced levels. You can view the episodes and podcasts online whenever it suits you. Free English Now is a comprehensive self-study English course which can be downloaded in text and also mp3 format so that you can hear what you are reading. Lesson text can also be downloaded in your native language along with English, making it easier to comprehend.