This is a simple, useful site for lower-level learners. It is just made up of vocabulary flash cards that you can click on to hear pronunciation. Simple, but effective if you don’t have access to native speakers who can pronounce words for you.
I see a lot of students who use WISH and HOPE incorrectly. The following lesson explains the proper usage of HOPE.
Here’s a Business English Podcast aimed at intermediate to advanced students of Business English. It’s done by two Canadian brothers. They explain a lot of useful words and phrases and the whole thing is done in a fun talk show style. Free study guides are available on the website. I think this podcast would be quite useful for students.