Sizing CD Cover/ Tray Inserts

i'm having a lot of trouble printing cd front covers and back tray inserts to size. does anyone know how i can size them correctly, or if there exists a program i can utilize to help me do so, or if there might be a website where i can print pre-sized ones?

 

bump...any help would be greatly appreciated

 

I use this for DVD inserts.It can handle a lot of formats.

http://jump.to/undercoverxp

Give it a look.