Kunaki deals exclusively with CDs and DVDs, as I'm sure you're aware.
I use them for my audio CD products. You have to first gather the files you'll be putting on the CD and burn them to a CD exactly as you want the Kunaki CDs to be.
If you plan to have your own custom graphics on the CD and case, make those first. The website FAQ gives information as far as to what dimensions to use.
If not, they have some decent stock image layouts you can use.
Now, once your CD is done, you have to go to their site and download their free uploader software. There's a link for it on there.
The software, once you install it, takes you through step-by-step on how to configure everything.
Basically, the software will ask you what type of CD you are making (audio, data, etc), and will ask you to either choose their graphics or use your own files.
It will also ask you to put the CD you made into the CD drive and it will extract the actual CD image from that. Everything will be uploaded.
There is no cost to upload and create CD products on their website.
Te only cost is $6.75 each time an individual CD is created/shipped to anywhere in the US or Canada.
As far as I can tell, it's $7.50 for most other countries.
If you're a programmer, or have access to one, they have an API you can use to integrate functions into your own site. I am still working to get that part done for my shit.