Just about any park pond in Northern NJ has largemouth and bass bugging is fun. IMHO, it is better sport in June when the post spawn bass are still shallow and the weeds haven't gone crazy, but it is worth a shot, Plenty of underfished gems for the explorer. Look at town, county, and state parks, WMAs etc.
July and August is good smallie and sunnie season to me. The Delaware is the queen of NJ smallie waters and just about any place from Trenton to the NY state line will have fish. In the day they will generally be in the riffles and runs - the bigger fish will be in the deeper pockets - and will be feeding on nymphs, helgrammites, crayfish etc. Therefore, get something big and natural colored down near the bottom (in the spirit of full disclosure I prefer spinning tackle to fish deep runs). During the day watch what shallows have tons of small fish. Go there at night and fish pencil poppers, white buggers, spuddlers, or some streamers. The smallies cruise the shallows in the dark to hunt minnows and that is better fly rod sport to me. Watch for fish breaking.
Most of NJ's larger trout streams run towards smallie water as you head downstream - i.e the Raritan and Paulinskill. The Muskie is the oddball and has it's warmer water above Changewater. The Passaic has good smallies in places. Check out smaller rivers where they have riffle/pool structure and avoid the long muddy bottom stretches - although a short muddy weedy stretch in an generally rocky bottomed stream can be the smallie hot spot.