Know (of)

Well, if you are a friend of Tom Cruise, then OK. But if you have never even met Tom Cruise then you might know of him, but you probably don't know him.

Know - without 'of'

If you know someone, then they also know you:

• you meet them either regularly or occasionally
• you know quite a lot about them
  (you probably know where they live)
• they know quite a lot about you
  (they probably know where you live)

Know of

If you know of someone, then they probably do not know you.

• you have never met them
• they have never met you
• if you know aything about them, this is probably because..
• you have read about them
• you have seen them in the media
• other people told you about them

The following would be more appropriate: