I use Reason 3 (at this moment, version 4 is also available)

It's a great tool to make your own music, by using many kinds of synthesizers, and effects. It's a little harder to use it for sound effects, but it will be possible as your experience increases.

Unfortunatly it's not free, [size=7px]but you can always start looking for a torrent [/size]:evil: ops:

I also use Goldwave, which is a wave-editor, that isn't free either AFAIK.