Not a pond, but Hugh Force Canal Park in Wharton has a canal with sunfish in it, and a annual fishing derby for the kids. That spot on Lake Hopatcong that Andre mentioned sounds good too. Joan Wulff has a great video for learning how to roll cast in a pond that I recommend watching if you are worried about trees and back casts being an issue.
http://midcurrent.com/videos/joan-wulff-the-roll-cast/
