For Ether and anyone that needs it.
Here's some info on how to play sounds in HL games...
Get HLSS to play the sounds and follow their instruktions:
http://www.hlss.us/
To get sounds from youtoob use a .flv converter:
http://www.flv2mp3.com/
To edit your sounds use audacity the trial version is fine (make sure to save the format in .wav or mp3 I forget which):
http://audacity.sourceforge.net/
To convert the sound to HLSS format to play use dbpoweramp (I'm using an older version of it tho and the sound file format needs to be a .WAV ~11kHz 16Bit Mono):
http://www.dbpoweramp.com/dmc.htm
People might use different things, but i use these tools.