This is my favorite audio book for learning Spanish.
Don't waste time with Pemsleur, get this first. This series gives you the best chance to learn Spanish. You will need a good verb book, and a good grammer book, but this series is essential. Really, it doesn't get better than this. I have tried them all. Use the others for supplementation after you listen to this series for a few times. This series finishes what the others start. Good job, Mark Frobose!