We just did a taste of this famous river for our sunset cruise, the 2 or 3 miles between where Muddy Run comes in and where the Maurice (pronounced "Morris") widens out into Union Lake. Featuring mature river birch, the banks are extraordinarily beautiful. We also saw clumps of blooming yellow iris and red-bellied turtles. A deep and blackish version of traditional Pine Barrens cedar water, the swollen current was a workout upstream, an easy coast down. The route is all sawn out.
We paddled rec kayaks 10-13'. One could often hear busy Rt 55 but we saw no garbage save where the fishermen congregated at the put-in. This is where Rt 552 (Sherman Ave) crosses the stream, only a couple hundred yards from Exit 29 on Rt 55, so the cars whiz by pretty good. The only parking is to pull over on the shoulder, so don't stumble when taking down your boat! We dragged them through the weeds to the little landing by the bridge.
This river will definitely be worth a full-day, downstream paddle with one car at Willow Grove and another at the Union Lake dam.
At this put-in there is nothing. Any type of business you need can be found in Millville, however. Following your outing, a visit to the Old Oar House Irish Pub in Millville will no doubt be quite refreshing. (see Pubcrawler.com) The town has built a beautiful staircase and plaza leading down to their waterfront from High St, their main commercial district. This would be below the dam, on the tidal portion of the stream.
Put in where Rt 552 (Sherman Ave) crosses the stream, only a couple hundred yards from Exit 29 on Rt 55. Turn West off the highway. The area is just North of Millville, NJ.
I use commentary from Gertler's Garden State Canoeing and maps from the big red Delorme Atlas & Gazetteer.