Vetrilo information is displayed in-game in the Guild Information section of the Social Tab, to view this information open the 'Social Tab' [default keybinding is the letter 'o'], click 'Guild' [tab], click 'Guild Information' [button]

If you do not already have Vent installed, please download it from the Ventrilo download page, for your respective operating system; be sure to download the client, and not the server!

Having Volume problems in vent? Some people are too loud and others are too soft? Try normalising your Ventrilo settings - see the Wow.com article How to normalize your Ventrilo settings

To learn more about how to set up vent, check out Kanthax's detailed information on installing Vent.