To join a specific channel/room type /Join #nameofroom

Common Commands

/part #channel_name  

Leaves the channel named #channel_name

/join #channel_name  

Enters the channel named #channel_name

/me laughs  

Sends "YourNickname laughs" to the current channel

/nick TrainMan  

Changes your nickname to "TrainMan"

/whois TrainMan  

Shows information for the nickname "TrainMan"

To talk on the channel just type what you want them to see and hit the enter key.