When I wrote my book, How To Make New Money When You Retire, I thought I should have it available to as many readers as possible. So putting the book on Audible made perfect sense.
The first thing you need to consider is the space where you are going to do your recordings. Find a place where you can keep the sound in and also look for space where sound won't bounce all around creating echos or other undesirable sounds.
You can use a closest where you can speak into a bunch of coats that will absorb the sound or you do what I did and converted a space in my garage, temporarily.
I found a spot that had fully insulated walls (without sheetrock to keep the sound reflections down) and then hung thick moving blankets or sound blankets found at JCX Expendables in San Francisco, CA. to deaden the sounds in my recording area.
Next, I needed a good microphone. I used a Sennheiser MKH 416 shotgun microphone . This is a professional microphone that will be more sensitive at the front of the microphone than on the sides and rear. That way, it does the best job at picking up just your voice and not other sounds in the room. Though this kind of equipment is expensive most of the time it can be rented from places like Lensrentals.com and other rental houses. So, you don't have to go buy it unless you are going to narrate several books.
The next piece of equipment I got was a good digital recorder. I used a Zoom H5. As a digital recorder, it is silent in its operation and this one accepts the XLR jack for higher end microphones.
You also need some way to mount your microphone so you can keep it at the same spot each time. I used a shock mount on a moveable arm but any kind of microphone stand should work.
Figure out the best time to do your recordings. Don't record on garbage pick up day or when the landscaping next door is being done. Use a time where your area is very quiet. A lot of times this is during the week in the mornings.
Turn off fans, fluorescent lights and other things in your area that make unwanted sound. Even consider what you are wearing that could make noises while you record.
When recording, keep a short distance between you and the microphone, about 4 inches. This will yield the best sound when you just want to hear a voice featured on the audio recording.
If you go on to the site ACX (Audiobook Creation Exchange) This is the site where you will ultimately upload your audio book to have it published on Audible. On the site, you will see the parameters that they need for your recordings. Things like how quiet the background sounds must be and how loud the maximum voice can be. As you record, you can monitor these levels of your recordings and its a good idea to create some samples and listen to them on your Audio Editing software.
Once you get sample recordings that work, keep the mic in the same spot and put some tape on the floor to make sure you can get back to the same position each time, when you take a break from recording.
For Audio Editing, I like to use Reaper. This is a program you can download and get started with pretty easily.
As you record and edit you will see that for just about every hour you record, you will spend two to three hours editing it. This will get faster as you go along but allow for the time commitment at first.
Hearing your book read aloud is an exciting feeling and I feel it is worth the extra work and expense. The overriding benefit is that it can create a new income stream for your books.