Chances are, the room you will be streaming from probably doesn't have the best acoustics. Echoey sound coming through your microphone is a good way to get your viewers to complain.
If this is a problem you see yourself running into, soundproofing foam can save your life. The foam will absorb any sound that is trying to escape to make an echo, and keeps it around where you are speaking into your microphone. Panels are cheap -- and a must for creating a good recording area.