As per suggestions by fellow WIS, you need to decide which case you like - Luminor or Radiomir. Then you need to narrow down to Historic or Contemporary range.
If I not mistaken, Historic are mostly handwound and no-date. Some with the second hand some without. As for me, I like to adhere to the true DNA of Panerai, thus the Historic range and I wanted the Luminor case. I like to see the Panerai logo on the dial and the second hand to me is not critical, thus the obvious choice is PAM000.
Anyway, like some said, go to an AD and try one on first and see which sing to you!!! Happy hunting for your first PAM.