I also enjoy the clear description of the serial/Oxford comma in this video. I will have to use this in my PR writing class next go around.
And this 'biweekly/bimonthly' video confirmed a pet peeve I have of using those terms.
These fun videos come out only about once a month, but are usually informative and interesting. So many people could benefit from watching these. There are a lot of them on YouTube, or you can find them using the link at the top of this page--go check them out!