Mike,
Don't know if it was explained above but the % symbol infront of the names in the sudo file is the reference for a group listed in the /etc/group file. So the line
%sudo ALL=(ALL:ALL) NOPASSWORD : ALL
When uncommented (remove the # in front if it exists) tells Linux to allow anyone in the sudo group access to ALL commands as root without a password. All you have to do is make sure this line is uncommented using visudo.
Then you would edit the /etc/group and add your username to the 'sudo' group line after the ':' on that line. If there is already another user listed simply add a comma to the end of the previous name then a space and add your username at the end (without a comma after your username).
Caution: This gives any and all users that are part of the sudo group complete root privileges without password requirements. If this is an issue you can depending on your distro instead use the %wheel group listing in the sudo file. If the %wheel stanza exists (same as the %sudo ... above) and there is a group named wheel in /etc/group you could use this in lieu of %sudo.
Hope this helps.