Here are some useful links:

Hudson Valley Gateway
Many of our hikes will be around the towns of Cold Spring and Garrison in the Hudson Valley.

Historic Hudson Valley
Discover the many national historic landmarks of the Hudson River Valley.

Metropolitan Transit Authority
Train Schedules, etc.

New York - New Jersey Trail Conference
They maintain many of the trails and sell maps.

About.com (backpacking/hiking)
Many links to great hiking info