If you're staying at the Embassy Suites, then the Rt46 and Rt202 stop is a couple hundred feet from the front door. The section of Parsippany Blvd where the hotel sits is aka Rt202.
As for drop off points, almost all of the Lakeland lines that pass through Parsippany go to the port authority terminal in NYC, and from there you can catch a cab/subway/train/bus to just about anywhere in NYC and the surrounding areas. There is a line that goes to Wall Street, but it's only in the early mornings and only stops about 2-3 miles away from the hotel.
Someone in the city can probably give you more pointers about points of interest, bad places to avoid, etc. I'm not really a city person.
edit: looks like the bus fares went up since I last rode. $6.75.
edit2: I forgot there's a train station in Mountain Lakes. If there's a hotel shuttle you can take, it's about 2 miles NE from the hotel.