The Animal Crossing Ahead Forums are probably one of the best resources for Animal Crossing information and discussion. I used to frequent the site a lot when I was playing Animal Crossing: Wild World and Animal Crossing: City Folk daily. I especially liked the Trades and Meetings Category for setting up online trades with other players or bidding on auctions or auctioning off items I didn't need anymore.
The site had been down for the majority of this year I believe but I found yesterday that it was back up and running. Check it out. As I said, definitely a great resource for information as well as a great place to find people to play with online.