CD case spine label; centring;

I am trying Disketch for making CD labels. At the moment I am using the free (domestic) version. I have three questions:

Can I print labels for the spines. of CD cases? If so, how? (This can be done in other label makers, but I cannot see how to do it with Disketch.)
In designing a label, is there any way of accurately centring an image or text block, vertically or horizontally?
How can I choose. the correct disc label format from the very long list of Avery and other formats for a standard home-burning CD such as a Maxell or similar one?

1-Yes, open Disketch > Create new project > select CD and Case on Generic Paper > you will see tabs, click the one for "Standard CD case - Back".

2-Unfortuantely, the program does not offer an option to center image or text as you have described.

3-It may depend on the labels you have purchased. For additional information, you may need to check out this link: http://help.nchsoftware.com/help/en/disketch/win/concepts_stationery.html