There you go. There is a help file in the GUI. The Party Lobby lags a bit in terms of # players as you probably know - eg, lobby says 7/10 and it might be already started. For that reason, the best way to go is open the first couple manually, then start it on auto mode. Set the menus to open SNG's with a max of 6 players registered (or whatever seems best for your game). If you close a SNG it won't try to open that again, so if you don't like the look of a game then just close it.
Just ask if you have any questions...