Things a company website should mention, prominently:

  • the name they want to use
  • what they do
  • snail mail address
  • address and opening hours, if they have a store
  • phone number
  • fax number, if they have one
  • e-mail address (or a web form, if they must)
  • when the site was last updated

It's amazing, but a lot of companies are missing several of these.