K.
I just bought a bike seat for my son. We ended up getting a "Wee Ride" - it's mounted on the rail between your seat and handlebars, so your kid can see what's going on. Great for balance on the bike, too. There are a couple of other front mounted seats (the other one we seriously considered was the "ibert"). You can find good product reviews of these two, plus all of the usual rear-mounted ones on amazon.com. I am very happy with the Wee Ride, but it will not work if you have a road bike where you're really crouched over.