This is a good basic overview of Lewis's work. While you may not learn much if you are well read I find myself wanting to read more after listening. I hope Reggie has not given up on this podcast as it has been a while since his last one. Also this podcast has convinced me to give Lewis's sic-fi a try.
This is a podcast that shows an indepth understanding of CS Lewis. He allows for spoilers, and incorporates non narnia material. Well worth your time. Really, no, dont leave, I promise you will learn something new at least