Do you press any buttons to talk to your friends on halo 3 or do you just talk and they automatically hear you? Which button, if you press any, are for talking to your team and talking to everyone?

In halo 3 if there are more that 5 people on your team.( i think that is the right number) then you have to push the d-pad to talk. On other games just simply make sure your mike is unmuted and just talk.

there is a slide switch... once it's turned to talk.... you just talk.