There are a couple of options with this one. The trail consists of a hard packed, easy riding abandoned railroad bed, which runs alongside the Lehigh River between White Haven, Pa and Jim Thorpe. It's a relaxing ride, and during the warmer months you can watch the rafters or kayakers on the river.
To start this ride from Jim Thorpe, take route 209 South from downtown to route 903. After crossing a bridge and making a sharp left hand curve you'll come to a stop sign (people making a right turn don't have to stop). Go straight through this stop sign and make a left turn at 0.4 miles from stop sign. Follow the road for 1.5 miles and park in the Glen Onoko Access Area lot. At the end of the lot go through the gate and head up the dirt trail. The distance to White Haven from here is 21.3 miles. There are many places to stop and check out the view along the way, or to have a picnic lunch. You can ride up to White Haven (a very slight upgrade the whole way) and back for a relaxing full day ride, stopping for munchies at the shopping plaza in White Haven.
Another option is to have your bike transported to White Haven by Pocono Whitewater Adventures. They're located on route 903 and for $15/person they will take you and your bike to the shopping plaza in White Haven. You can then ride into Jim Thorpe and call them from the grocery store that is at a sharp right hand curve on route 903 just before you go over the bridge leading back to route 209. That's where they'll pick you up. I've put a link to their web site in the links section of my homepage.
Or you can try putting a vehicle at either end of the trail yourself so you can get back to the starting point, but that's a hassle (I know- I tried it myself when I only wanted to do the ride one way and didn't want to pay $15!), so I'd use the shuttle service.