I made a flash announcement here when the audiobook version of Dancing on the Wind finally went live two weeks ago, but I wanted to ruminate a bit more on the process. This is the third audiobook that I've produced, and each time there have been more things to learn.
Though I'm still a novice, for me the key points are:
1) The first big challenge is finding The Voice. Someone I like listening to, and who will also appeal to regular audio listeners. I have a fondness for a lovely deep male voice (calling James Earl Jones!!!), but a man with a naturally deep voice will probably have trouble with lighter female voices, just as a woman with a lighter, higher voice might have trouble with male characters. A skilled narrator doesn't actually imitate multiple voices, but implies them through accent, inflection, pacing, and other verbal tricks. Doing that consistently throughout a full length book takes a real pro.