live cd - How can I check the integrity of a downloaded Ubuntu CD?

I've just downloaded a CD image of Ubuntu. I know the installer has a check CD option, but how can I check that the image is good before burning it to CD?

First look up the hash of the ISO you download here:

(or in general find your Ubuntu release here)

Then check the hash by following this video or these instructions:

After checking the hash it's safe to burn the image to CD/DVD.