If you just want to set out on your own to explore the city, there's lots to see in the Big Apple. Visitors staying in a midtown hotel can walk up the east side of Central Park and just north of 72nd Street there is a place to rent bikes. By far the best time to see the city on a bike is on the weekend, since the traffic is light. Any direction is the right one. But if you're starting in midtown, you need to have an idea of the distance you want to travel and the special things you want to see.
Cyclists ride through New York's Central Park.
Biking is a good way to take in a lot of New York and get a sense of its history, architecture and how neighborhoods blend together. One way to do this would be to ride up the west side. Get onto Riverside Drive at 72nd Street, take that up to 165th St., and go up the hill to Fort Washington Street. You might want to ride across and check out the view along the Palisades. If you want to keep the ride urban, go past the George Washington Bridge into Fort Tyron Park, ride around and start heading south, drifting eastward as you go through Harlem and the Upper East Side.