I am a mac user and these are my favorite programs: adobe premiere cs3 for video editing: audacity for sound editing; mpegstreamclip for resizing and converting audiovideo files; name mangler for well, renaming files, and; subsfactory or miyu for writing subtitles. Also, synapsen hypertextual index for compiling research materials was a lifesaver when i was writing my thesis. In a blink of an eye, this software can automatically generate your bibliography. Now I sound like a salesperson, haha!
There are various online softwares and freebies which are simply fabulous such as:
http://citationmachine.net for generating your bibliography
http://ccmixter.org for creative commons music
www.freesound.org/for creative commons sound effects