Start from where it all started. Gene Vincent, Eddie Cochran etc. Most of those songs are pretty easy to transcribe since they follow the prototypical I,IV,V progression. Sometimes I feel like I'm in over my head when I try to learn a Setzer song so, I go back to those artists I mentioned and try to learn those first to get a feel for it.
I HIGHLY recommend that when you are learning a song, play it from Windows Media or any other audio software and slow down the track to hear it note for note. Trust me, it helps a lot.