I'll second the prior motions on the Gossen stuff.

I picked up a Lunasix last summer (less than $30.00 on ebay). Its my first light meter, so I wanted to keep it simple. I love the thing!
I had never used one nor seen one used and it didn't come with directions.

So, what did I do? I asked someone here and quickly got some great tips and a website referral.That website had the entire instruction manual posted. Bingo and Parchese, I was in business...

I wish I had been introduced to decent cameras when I was younger, instead of cranking out terribly exposed vignetted instamatic junk.

Good luck and remember to have lots of fun teaching and shooting with your son.