If you have access to the internet (looks like you do) you already have thousands of books available to you for free. You can go to a site, find what you want, and just start listening.
If you have an MP3 player, chances are it has enough memory to hold several books. If you don't have an MP3 player, you may consider getting one after you give audiobooks a try.
Booksshouldbefree.com is an excellent site that uses librivox recordings, but organizes the best ones for you so
Loudlit.org - very high quality recordings independent of librivox
And where will you be listening?
In the car?
In a hammock?
While you walk the dog?
Before you fall asleep at night?
Give it a try!