Hi! I decided to write this short Toturial for ppl who had some problems with using Ventrilo.
Lets start!
First We need to install Ventrilo ver. 2.3.0
You can download using one of this link:
http://www.ventrilo.com/download.php

After installing it (there should be no problems with that) - start it ;)
To create new user of Ventrilo press:

Then:

And then write ur nick (the one you'r using in game) and press OK:

Now press OK again... you dont need to write anything else:

Now press:

And then:

Enter whatever name you want and press OK:

Now enter all just like bellow (no password) and press OK (2):

Now press:

Check (1) to use Push-To-Talk function... now in field (2) press button you'r going to use to speek (i'm using F5). If other ppl will have some problems hearing you, you should use (3) to amplify your Outbound (all can look little diferent... i wrote that toturial on ver. 2.1.4):

Now press OK. And Connect!!
You should see that:

To enter channel just click twice on it (our channel is Hellraisers). To speek just press and hold button you selected in Setup (for me - F5). Now dont close Ventrilo, just open World of Warcraft. You can use Ventrilo while playing WoW!
I think thats it! Enjoy!!