Student teachers might find useful material for their classes in the BBC Learning Zone Broadband Class Clips archive.
Broadband Class Clips is a collection of short video clips available for streaming in classrooms. The clips are gathered from BBC programmes such as Bang Goes the Theory, Springwatch, The Private Life of Plants, etc., and are designed to match school curriculums.
You can search by subject, by level (primary or secondary) or by keyword. Some of the clips would also be suitable for using with college-level classes.