Dick's Dock in Metuchen
Restaurant is totally kid friendly.
I agree with mrsossisme, very diner-ish. Reminded me of a beachside diner (or something like that). The waitress/owners/chef's wife<?> was very nice and friendly, informally so. Menu is extensive as described by trent.
Seafood is fresh and good. I also enjoy the simplest dishes the best.Prices, on the other hand, are not inexpensive.
I enjoy my visits there.
The variety of seafood dishes is fairly broad. Some are simple grilled or blackened preparations and some are more complicated (but be careful -- some of the combinations aren't necessarily coherent). Seafood pastas, seafood with rice, fried fish -- generally all the usual suspects. The assortment of available fish is decent, but rarely exotic. I think the special (always on the menu) is a potato-crusted salmon doused in red-wine syrup. The filet is egregiously large, the syrup is sugary sweet, and the dish takes a long time to come out of the kitchen, but it suits my particular tastes. All said though, I usually enjoy the simplest dishes most.
I've never eaten with anyone who has ordered a non-seafood dish (I assume such options are on the menu, but I could be wrong).
As for children -- the place is entirely informal and kids should be welcome. Their enjoyment of the meal might be hurt by the pace of service, which is (in all of my experiences, and regardless of whether you order the salmon) really, really slow.