Cycling to Work

I've been sent a copy of the book, Cycling to Work - A beginner's
guide, to review. Has anyone else read it?

Just for devilment - here's the helmet section:
"There is some debate about the pros and cons of wearing a helmet
(there is no legal requirement to do so in this country); but if you
do land on your head it could save you frombrain damage."

There then follows some advice on the correct fit.