I love Scribd. It is Netflix for books and audiobooks. For 8.99 a month, you have access to a ton of great books for one membership. Here is my starter kit for you if you do decide to invest in Scribd. Audible is great, the user inference is alittle better, and they have a slighter bigger selection. It can't beat Scribd's price though and the selection at your fingertips. This is a fantastic investment in yourself and learning is key to success.
My favorite audiobook on Scribd: Linchpin by Seth Godin. Opened a lot of doors and beliefs I've been struggling with lately.