Here’s a list of resources that I’ve collected over the years. Let me know if any don’t work any more, or if you have some others that could be useful for others.
General
British Council’s Learning English Kids
Listening
British Council’s Learning English Podcasts
British Council’s Podcasts for Professionals
British Council’s Learning English Elementary Podcasts
British Council’s Learning English Kids: Listen and Watch
The British Council’s The English Channel
British Council’s Audio Zone < B2+
British Council’s Video Zone < B2+
BBC Basic Grammar with 6 Minute
Grammar Girl’s Quick and Dirty Tips (Education–Grammar)
TED Talks (Ideas worth spreading)
BBC’s Scott Mills Daily podcast (B2-C2)
BBC’s Radio 1 Best Bits with Greg James podcast (B2-C2)
BBC Learning English 6 Minute English podcast (A2-B1 and beyond)
BBC Outlook podcast (A2-B1 and beyond)
Writing
Cambridge English Write & Improve
SKETCH free academic version (only academic corpora; good for essays and other formal writing):
SKELL (free simplified version of SKETCH):
SKETCH full (4.83 Euros per month)
Just The WordA free, simplified concordance tool based on the British National Corpus
University of Queensland Course on improving your writing
Vocabulary/Lexis
Oxford Advanced Learners Dictionary (OALD)
english-corpora(This is where all the magic happens. Choose COCA, iWeb or BNC.)
Longman Learners Dictionary of Contemporary English
SKELL (Sketch Engine for Language Learning)
Quizlet (make flashcards; practice with spaced repetition; play games)