If you're not too far, a great place to get a bike or some parts/clothes/etc. is the Flea Market at the Velodrome in Trexlertown, PA. It's not far from Allentown and it happens once in the spring, and again in fall (April and October, IIRC). I got my current bike there last spring, a Bianchi Veloce (that normally cost $1400) for $800.
I love Mercer County Park in West Windsor, Six Mile in Somerset and Clayton Park in Imlaystown. Heard there was some good North Shore stuff in Allaire but I never found it, just lots of deep soft sand.
I have a decently old Schwinn Moab and love to get out to Mercer County Park by the Marina. They have millions of trials back there if you can find all of them. Difficulty can increase pretty severly if you find the right spots.
Had one... well it was a Toys R Us Schwinn def not the Schwinn of back in the day. But I liked it and I used it quite a bit, but not in woods and stuff just liked to ride around town and some further towns in my area. But it was stolen from out of my garage one Saturday morning someone left the garage unlocked. Seen the kid riding it one day months later, I knew it was mine it was missing the water bottle and it was the same color combo, it's not like it was a common bike either very easy to pick out. I knew it was mine when he seen my car pass him he took off without me saying anything must have remembered the car in the driveway as he rode past it.