The Smashwords publishing process was really easy to do, and resulted in the file being made available in several formats. I wish I had published through Smashwords earlier.
The Kindle publishing mechanism is also straight-forward - however it can result in errors without any indication of that the problem is. After trying several things, I believe I've figured it out.
One big downside of Kindle publishing? You can't set a price of free, like you can through Smashwords. This means people who download the book on the Kindle will be asked to pay 99 cents (their minimum charge for an eBook). Smart Kindle users will grab the .mobi file from Smashwords and email to their Kindle account.
The Smashwords release is now online. The Kindle release is awaiting review and should be online soon.
After one day of Smashwords availability, the book has already been downloaded 70 times. Nice!