ALREET NOOBS.

HERE R HOW 2 UZE MUMBLE. IT NOT HARD:

Don't bother with the audio wizard, skip that. Go to configure -> settings, "User Interface" tab and enable "Expert Config" now you'll want the following settings:

Audio Input: Transmission, Transmit - Push to Talk
Shortcuts: Add, Function - Push-to-Talk, Shortcut - Whatever you want to push to talk
Messages: Uncheck the whole "Text-to-speech" column unless you want to be pissed off
Overlay: This shows who is talking on Mumble, and shows it over the top of TF2. I have it enabled, and have unchecked "Always show self" and changed the mode to "Show only talking"

Now, Server -> Connect:
Label: FB
Address: fakkelbrigade.eu
Port: 64739
Username: whatever you want your name to be
Password: thebrigade

Click "add", then "Connect" - then join the "Construct Gaming" channel (it's alphabetimically sorted) - done!