For distribution of physical CDs or digital downloads, the first thing you need is a UPC, which stands for Universal Product Code. It's a 12-digit serial number with bar code that identifies a product, in this case your CD. There are several ways to get a UPC code. While you can easily spend $750 to secure one, you don' have tot. There are ways to get them for free or next to nothing.
The easiest way to launch your album is to sign up with cdbaby.com, a highly reputable music distributorship for independent artists. Although much of the music market has trended toward digital downloading, there is still a substantial market for packaged CDs. Cdbaby is the only resource that handles packaged CDs. And it will not only assign you a UPC code for $20, in addition to the basic $35 setup fee, but will distribute your work via its website. Cdbaby requires only five copies of your CD to get started. If your album sells, it will also help you with reasonably priced short runs. Cdbaby also funnels music to iTunes, Rhapsody and other download retailers.
A newer addition to the indie distribution business is tunecore, which gets high marks for funneling indie music to streaming audio sites and 19 download retailers, including iTunes and Amazon MP3. Tunecore charges $9.98 to launch a single to all of its partner stores and $46.99 for an "unlimited album" package which allows for an infinite number of songs and access to all stores.