Putting one's own songs on Amazon as an MP3 download

In My Humble Opinion (IMHO)
#1

Question for any Straight Dopers who have expertise in this:
I’m a freelance music composer. I hope to put my own compositions on Amazon as the 99-cent or $1.99/song downloads the way many other music artists do, but haven’t a clue how to do so. I also don’t know how to copyright and publish a music album.

Any advice would be much appreciated.

#2

Digital Music Store

If you are an artist, label, or distributor, and would like your music added to the Digital Music store, contact one of the following distributors to assist you in making your music available for sale in the Digital Music store:

For more information about cdbaby, go to www.cdbaby.com.
For more information about REBEAT, go to www.rebeat.com.
For more information about INgrooves, go to www.ingrooves.com.
For more information about redeye, go to www.redeyeusa.com.
For more information about The Orchard, go to www.theorchard.com.
For more information about TuneCore, go to www.tunecore.com.
For more information about Virtual Label, go to www.virtuallabel.biz.

http://www.amazon.com/gp/help/customer/display.html?nodeId=14061761

#3

CDBaby is who I use. I like them.

You are your own publisher and you already own the copyright for your works.
If you have goals that include having your music performed by other artists, placing your music in movies or T.V. or in advertising, you’ll eventually want to register with a performance rights organisation (PRO) like ASCAP, BMI, or SESAC. For now, you just want to sell your own recordings of your work, it’s not necessary to register with a PRO.

CDBaby has me on Amazon, iTunes, pretty much every possible digital retailer. They also give you the option to opt out of digital distribution or to pick and choose which digital retailers you want to work with.