For some reason, Apple changed the way that printing is handled in 10.5 and probably 10.6 (haven’t verified yet) so that non-admin users cannot add printers, similar to Windows.  But they also are unable to unpause the printer or cancel print Jobs.  Below is a fix that i found that seems to solve the problem.

In \private\etc\cups there is a file called cupsd.conf, you will need to edit this file.

About halfway down there is a Section:

You need to get rid of the portions from <Limit CUPS … </Limit> and also <Limit Pause … </Limit>.  You could delete these sections, but I just comment them out so that these sections are still there, just ignored.  When working with Config files,  I always comment out instead of deleting as it allows me the ability to quickly reactivate portions if I need to.

When you’re done the section should look like this:

You can either restart the CUPS Service, or Restart the computer.

Non-Admins should be able to add printers and modify print jobs now.

If you’re doing this on a bunch of computers you probably want to  use Apple Remote Desktop.

Edit the cupsd.conf file on one computer, test that it works and does what you want, then copy it to your computer running Apple Remote Desktop.

In Apple Remote Desktop, select the computers that you want to send the file to from your Computer list and click Copy in the taskbar.

Add the cups.conf file that you saved from the other computer by dragging it to the items to copy part of the window, set it to be saved in /private/etc/cups/ and to replace the existing cupsd.conf, and to inherit persmissions from the folder that it’s copied to.  These settings are shown below:

Now Click Copy and it will send the modified cupsd.conf file to all of the computers you selected and tell you whether it was successful or not.  Again, you will probably also want to restart these computers to ensure that the new settings take effect.