It really depends on what he would be using it for. There are some basic ones at the lower end of the scale that are fine for home vids, but I would def go for mini-dv. Tape stock is cheap and is easy to edit. The cost rises depending on added features like optical zoom, image steady etc, 3CCD etc. Has he used them before? What's your budget?
He has used one before. He's a teacher and does a bit of video filming/editing in school. He borrowed one from school last October and made a great film of our kids on holiday. he'd like to do more of that.
Not sure about the budget. Whatever it costs to get a decent one without going over the score, I suppose!
Is there any way you could find out the make/model of the one he used? Then check if it's in your price range and what that specs are. If he's seriously into filming/editing he may feel a bit limited with some of the lower end models. I guess you get what you pay for!
Do you have editing software at home? If he's a teacher he can get an educational licence on some of the industry standard edit suites like Final Cut Pro, Sony Vegas or Avid.
There are some good review sites I can link you to if you like but you may feel a bit overwhelmed if you're not into that stuff!!
I do this for a living (not sell camcorders ) so I use the more expensive semi-professional models in short films. These tend to have more whizzy stuff, but I guarantee once you start you get the bug!