That being said, here are a couple of links.

Diaphragm Breathing/Speaking: http://www.roleplayingtips.com/readissue.php?number=3

Khargyraa Techniques: http://www.youtube.com/watch?v=uCom9ZCJAmE

The best tip for the Khargyraa stuff is just to watch that video and maybe this one and then wing it for a while, trying to get the sound right. If you manage it, try just saying some stuff in a normal voice and note the difference. It is immediate and surprising.

This link is nice because the guy is such an amateur! He clearly learned, like, one technique (probably from youtube) and then posted his immediate results on youtube, so it's a good starting point. http://www.youtube.com/watch?v=X54KBdi5_xg