Here's what happens when you look for and join an existing hangout. You could start with the one at the top of this web page, billed as the world's longest hangout, it's been running since July 20th, 2011.
In my case (and for this example) I looked for a smaller hangout and found one hosted by Frank Poliat, a nice guy with several helpful folks in the hangout.
Checking Frank's hangout post before joining the chat, I saw only one other person was in there—looked like a good place to start (and it was).
Ready to enter, I clicked ...