I modified this from an original template I found on
www.damnprinter.com - the original was a bit too hit-and-miss for me and I wanted to make it as foolproof as possible.
It enables you to print a label directly from Photoshop to a Canon Pixma printer using Tray F with a full label print (i.e. no thin white rim in the middle and none at the edge). The file is set up for Verbatim DVD +R 16x full face printables (hole 21mm, edge 119mm) so you will probably have to modify it for other disc types but it's fairly easy to do. The key factors are the guides that act as a crosshair for the center of the disc and the width of the label itself when you drag it into the file.
This seems to work consistently for me but use at your own peril!
Instructions
Open both this PSD file and the label JPG in Photoshop
Resize the label JPEG to 1417x1417 pixels
Drag the label to the Label Print window, put it in the correct layer and snap it into place on the crosshair (you must have Extras, Snap and Snap To / Guides turned on in PS).
Make sure the "Hole" layer is visible otherwise the printer will print over the hub on the CD tray - this gets messy.
If the label image has any other content than just the label itself (e.g. a graphic surround or other symbols) then turn on the Outer Border layer.
In Print Properties, make sure the Paper Size is set to CD-R Tray F on the second tab (as per the screen shots below)
Print the label.
Let me know if you have any feedback (good or bad) ...