A printer pool is a set of more or less identical print devices that appear to the user a single printer. Each print device is associated with its own port. In a printer pool, there are multiple ports associated with a single printer. Since there is only one (logical) printer, all the print devices in a printer pool use the same printer driver. Thus, print devices in a printer pool must be identical in the sense that the printer driver for the printer pool works with all the print devices. Also, they should have the same set of hardware features. The user doesn't get to select which print device in the pool to use, so, for example, if one has a duplexing unit and one doesn't, double sided printing may or may not work depending on which print device happens to be used.
To enable printer pooling:
Open the Properties of the Printer to be pooled
Select the Ports tab
Add a check mark to the Printer Pooling check box
Click on the port(s) corresponding to the print device(s) that are to be part of the pool to add a check mark to them
Click OK