Gosh, I've been making prints with letterpress for something like 6 years now. I started out by taking a class with Dikko Faust in New York. But mostly I've learned through hours on press.

Vanderblog (http://vandercookpress.info/vanderblog/) and Briar Press (http://briarpress.org/) are good online resources and their are others as well.

Dan Morris from The Arm in Brooklyn (http://thearmnyc.com/) has provided tons of guidance over the years. The Arm has weekly workshops in Brooklyn and lets folks rent time on press there. That would be a great place to start if you are looking to try letterpress and in the North East US.