I'm just getting back into this after a few years, too. And the best thing to do is research. Look up the currents sets (Diamond & Pearl through the latest are all the legal ones) on Bulbapedia or Pokepedia and look at what cards are out there. Also, what kind of deck do you want to make? Pick one or two elemental types that you like and try to build something up. You can't expect to be just told what's good because there's a lot that's good. Otherwise everyone is just going to roll their eyes at this post while it gets pushed to the back of the forum over the following two and half weeks. You just need to get out look for yourself and you'll find what you're looking for.
And yes, I would be interested in trading.
