I did end up getting impatient last night because it wasn't working yet, so I started doing a little more reading, and ended up following these instructions instead. Instead of creating a new CNAME record, I just had to edit the 'www' one and have it point to ghs.google.com - and it works. I don't know if the other way would have worked, because I didn't wait to see, but these instructions are very clear and easy to follow.
Then I read this:
With GoDaddy Total DNS Control, you have 2 lists - "A" and "CNAME". The "A" list needs to be empty, and the "CNAME" for the "www" alias needs to be at the top of the "CNAME" list.So, I deleted the one item in the "A" list - though I really don't understand it, and I did copy it to notepad first so I can put it back if I need to.