I have the 3G Nook and love, love, love it. My kids loved it so much that I bought one of the refurbished 3G ones for middle DS for christmas. (Well, I picked it up but Grandma and Grandpa paid for it and gave it to him.)
If you eventually get a second Nook sharing books on the same account is definitely possible as long as you don't mind your kids having access to your literature. That's the reason I set DS up with his own account. Some of my romance books are a little too racy for a 10 yo.
If you can afford it definitely go for the 3G - it's so nice to be able to download a book where-ever you are. We were on vacation at a really old, really basic beach cottage (so no computer, nevermind wi-fi) this summer and DS was in bed and finished the book he was reading and we just went online and bought him a new one right on the spot.
I have one of the Oberon covers and picked one up for DS as well. I like that they're so well made. I have Celtic Hounds and DS has the Sky Dragon. http://www.oberondesign.com/nook_v1.php
If you eventually get a second Nook sharing books on the same account is definitely possible as long as you don't mind your kids having access to your literature. That's the reason I set DS up with his own account. Some of my romance books are a little too racy for a 10 yo.

If you can afford it definitely go for the 3G - it's so nice to be able to download a book where-ever you are. We were on vacation at a really old, really basic beach cottage (so no computer, nevermind wi-fi) this summer and DS was in bed and finished the book he was reading and we just went online and bought him a new one right on the spot.

I have one of the Oberon covers and picked one up for DS as well. I like that they're so well made. I have Celtic Hounds and DS has the Sky Dragon. http://www.oberondesign.com/nook_v1.php