Hell, and welcome, Matt!
Regarding Teamspeak: Basically all you really need to know
is in that thread
We do use push-to-talk, simply because voice activation tends to be quite uncomfortable for your playing partners (if you happen to eat something, breathe heavily or yell at your cat). I personally use left-ctrl as my ptt key, but it really depends on what your control layout is like (mine is like, heavily modified compared to Arma default). I know quite a few people use mouse buttons to deal with comms as well.
VON: welcome to Hell on Earth. That thing works when it wants to, and is not really the best around. You can't really test it outside of a server. Though, really, if you're not using a beta-patch, you shouldn't encounter any more problems that the average dude (which means, once in a while, you might go mute but there ain't nothing you can do about that). Emphasize on don't use beta patches
. They will mess up your VON almost everytime.
Regarding the upkeep of the server: it all happens here
. As much as Bodge likes to receive donations to redecorate the exteriors of the Party Dacha, though, you might want to play with us a bit more before deciding if it's worth your money. Contributing financially is not mandatory. The Party accountant might or might not kill me after reading this.
Finally, you can join us on the FA Skype Permachat
. You can get all the help you want there, as well as informal sessions of Arma when they happen, but also of a lot of other games.
See ya around!
Edit: Oh, and you being lost with comms and all that? That's normal. The first sessions always tend to seem a bit messy, for everybody. You'll quickly get a hang of it.