A keynote of all marketing, but especially Internet Marketing:

What do they want to know?

Your customers and prospective customers, that is.
To figure this out can be as easy as putting yourself in their shoes.
Violations are common.
For example, I went online for a new dry cleaner’s store hours, as I wanted to pick up some pants before work.
You can’t find out.
It isn’t on their website, and it isn’t on their Google Places page. Their “Mission Statement” is featured, but not the hours of operation!
Now that shouldn’t be very hard to figure out as a key piece of information, is it?
Put yourself in their shoes.
If you still can’t figure it out, ask them!