How do I add a Chat Room or a Channel? (Dasher)

You can choose which channels you have open by clicking on the My Channels icon (2 babyblue text balloons) in the Menu Toolbar. A dialog will open and you can scroll down as you click on each channel you wish to join. A check will appear in the box. To remove a channel, click the folder and uncheck the box for that channel you wish removed.
  

Some of these channels are restricted to Groups. You have to be a member of such a group to enter these channels.
For more info about groups read "help group-commands" 

Command method: 
You now need to know the channel number you wish to add.  "help Channels" for a list of ICC channels.   To add the Experienced Help channel you would type '+channel 2' in the Main Tab of your Channels Window.
To remove the Experienced Help channel you would type '-channel 2' 

Dasher Helpfile on Channels: CLICK HERE