Start in Concord and head south on Route 3. Follow into Hooksett, and turn left onto Route 27 (Whitehall Road). Follow this out to the end at North Beach. Make a right onto Rt 1A, and follow that into Hampton Beach.
This route takes you from New Hampshire's state capitol to the Ocean. The start down Route 3 is a typical two lane blacktop going through some smaller towns. There are a few lights along the way, generally traveling along at about 40mph. Route 27 provides varying roads and terrain, with slower stretches at the start, gradually speeding up to 55 in Raymond where you will find a fun four-laned stretch of road with slow s-turns. A sport bike or a cruiser will enjoy that portion just past the interchange with Rt 107. The road slows down gradually to the point where you are slowly cruising through historic Exeter. It gets crowded from there to the beach. Heading down from North Beach it gets beautiful, with mansions on your right, and the ocean on your left. Stop at Hampton Beach in the summer to enjoy the boardwalk.
The ride back follows Route 1 north (nothing really special here), then takes Route 4 west back to Concord. Rout 4 is known as the "Antique Alley" with many shops selling antiques and other curios. If you just want to ride, the road is in great shape, with speeds varying from 40 to 55 - enough variation to keep you from getting bored. Take in the rolling countryside and enjoy the ride.
I own as sport bike, my neighbor a cruiser - this is a road we both like to ride on together, as it is fun for both types of bikes.
This road has a few straight stretches, but for the most part is comprised of rolling hills and easy going curves. Pavement is in good shape, with lots of construction having now been completed. There are weaker spots, primarily in Exeter, where it gets a bit bumpy.
Nearly every town has something good to offer for food. My favorites are Interested in guns? You'll be driving right past Sig Saur in Exeter.
New England Dragway in Brentwood is also a fun stop. If you want to see a concert, you can always try the Hampton Beach Ballroom.
Motorcycle Road Additional info
It can get hot at the beach. Hampton Beach has lots of pedestrian traffic. Often you are not traveling at more than a snail's pace, so be prepared. If your bike overheats easily, you may want to come when it's a bit cooler out.