To improve your listening skills you need to practice regularly. Here are some resources to help.
Listening Practice & Resources
British Council’s Listen and Watch Page is one of the best resources for practicing English listening.
Randall’s ESL Cyber Listening Lab has many listening tests, grouped by level.
The University of North Carolina has a page of Academic Listening Strategies.
English Central is a freemium site (offering a certain amount of free content with an optional paid subscription) that offers videos followed by exercises to test comprehension and pronunciation.
Speaking Practice & Resources
Here are some resources brought to you by the English Language Centre:
The University of North Carolina has a page about Academic Discussion Strategies.
Pronuncian.com offers several resources on American English pronunciation.
Splendid Speaking offers some excellent speaking resources, including speaking guides for popular English speaking exams. You can try some for free, but continued use requires a paid subscription.