Omen: http://files.wowace.com/Omen/ Scroll ALL the way down to the bottom and dowload the one with the biggest number to stay updated! Enjoy!
Ventrilo: You can download this at http://www.ventrilo.com/download.php We use this program for raiding. While you do not necessarily need to be able to speak on it, we want you to be able to listen to directions while fights are explained.
***Highly Recommended*** Deadly Boss Mods: http://wow.curse.com/downloads/details/4940/ This addon lets you know when bosses are about to do scary dmg in fights...we always have at least one person running it per raid. I have not myself used this mod but it is supposed to be very useful on encounters where it is important that you don't get too close to anyone (which is even more important I think as we progress). I plan on downloading it shortly!
If you feel uncomfortable clicking on any of these links please go to the Curse website and download there, Thanks!
If you are downloading from Curse, make sure to use the MANUAL downloader.