The two links below have episodes 2 and 3 of the original Star Wars Radio Drama. These two episodes {Provided by BlueHarvest.net} have the official "Lucas Approved" back story of Princess Leia and her father's involvement with the stolen Death Star plans, Captain Antilles and his ship The Tantive IV, and the reason for being at Tatooine at the start of A New Hope.
CLICK HERE FOR: Radio Episode 2 "Points of Origin" Ra, 3.2MB
CLICK HERE FOR: Radio Episode 3 "Black Knight, White Princess and Pawns" Ra, 2.9MB
They are very good!
Enjoy.
Blue Harvest has the full first four episodes of the Radio Drama posted HERE .