Real good run down:
To install printers to groups of users or computers by using Group Policy
Open the Administrative Tools folder, and then double-click Print Management.
In the Print Management tree, under the appropriate print server, click Printers.
In the results pane, right-click the printer you want to deploy, and then click Deploy with Group Policy.
In the Deploy with Group Policy dialog box, click Browse, and then choose a Group Policy object.
To assign the printer connection setting to the GPO, do one or both of the following:
As a per-user setting, select the The users that this GPO applies to (per user) check box.
As a per-machine setting, select the The computers that this GPO applies to (per machine) check box.
Repeat steps 3 to 6 to add the printer connection setting to another GPO.
To use the PushPrinterConnections.exe file
Using Group Policy Management console (gpmc.msc), right-click the GPO with your printer connections settings, and then click Edit.
In the Group Policy Object Editor tree, navigate to one following locations:
If the printer connections are deployed per-machine, go to Computer Configuration, Windows Settings, Scripts (Startup/Shutdown).
If the printer connections are deployed per-user, go to User Configuration, Windows Settings, Scripts (Logon/Logoff).
Right-click Startup or Logon, and then click Properties.
In the Logon Properties or Startup Properties dialog box, click Show Files.
Copy the PushPrinterConnections.exe file to this location and then close the window.
In the Logon Properties or Startup Properties dialog box, click Add.
Type PushPrinterConnections.exe in the Script Name box.
If you want to enable logging, type –log in the Script Parameters box. Log files are written to %windir%\temp\ppcMachine.log (for per-computer connections) and %temp%\ppcUser.log (for per-user connections) on the computer on which the policy is applied.