I am doing English Language (AS) for the Cambridge International Examination. Since most of the users here are from England, I want to ask if anyone has any helpful websites concerning English Language for AS.

I looking for websites which would provide any information on:

Commentary
Directed Writing
Discursive/Argumentative Writing
Radio Scripts
Diary Entry and...
Descriptive writing.

If anyone has experience in the AS English Language examination, I would appreciate tips, opinions or any helpful input. Thanks!