This is a quick one. If you need to figure out what groups your user account belongs to you can simply use the groups command from the command line:
kdmurray adm cdrom sudo dip plugdev sambashare lpadmin debian-transmission smbmedia smbbackups ccnet
You can also use this command to find out what groups any other users belong to. This is particularly useful when setting up new services or new network shares and you need to confirm which groups the user belongs to.
kdmurray@titan:~$ groups ccnet
ccnet : users ccnet
Try to find yourself a use for the groups command this week!