Do you know how you'll hear a popular song in a movie, but the refrain repeats for longer than normal?

Does the editor do that himself, or is there somewhere I can get it?

Is there a cool place to get good music and sound effects for films?

That should be done by the audio engineers on the project. There are many
places to get good music or sound effects, but they are usually costly.

Sound effects is something you could easily try yourself with a good mike.
Some of the more interesting effects in the past have been made my
combining sounds, reversing them, slowing down or speeding up and other
kind of distortions etc.

Most people advice to hookup with some music makers who are trying to
get their music out in the world. They might be interested in giving you
their music for free in return for credits and a link on your website for example.

What about sound effects?

What kind of sound effects? As I said, most are simply made by recording
ordinary sounds (machines making noise, flushing of a toilet, rain hitting a
window, book falling on a table, etc. etc.) and then altering and/or combining
them in an audio processing application.

I recently read for example that Darth Vader's breathing was recorded with
a mic inside a scuba tank.

Something like a "zzzeerrooowhhoosssssmmpp!"

:D

Seriously, something like you see in 24 when the name of the location is displayed on the screen and each letter is accompanies by an electronic sounding tick. Stuff that is ephemeral and not rooted in the "real" world like a door shutting or something.

Matt,
Try a google search under 'Sound Effects' Or Sound FX. Plenty of free ones available on the net.

Heya:

For sound effects and some royalty-free music, try Sound Dogs (http://www.sounddogs.com).

If you want to have music made specifically for your film... let me know. :)