I'll chime in here with a few useful links for advanced movie makers:
1.
Detonation Films ........ free tutorials, explosions, green screen footage, special effects footage. These guys just love blowing stuff up.
2.
Deltaweb's Radio 1940 .... Voiceover summaries of each day of BOB in a 1940 BBC news style.
3.
Vidiots' YouTube Video Channel ........... Lots of cool green screen effects. Bullets, blood tec.
4.
SoundDogs sound effects .............. All the sound effects you'll ever need.
5.
Neo's Clip Archive ............ Free footage, clips, green screens. backgrounds, sounds, catagorised with previews
6.
Free Music dot com .............. Free & almost free music catagorised into themes.