It's very easy!
But you are only doing half the job. The next step - having made the printer shareable (if that's a real word) on the client to which it is connected - is to open the Printers and faxes folder on the other clients. Select "Add a Printer" from the task pane. Click Next. Select the "network printer" radio button. Leave it set to "browse for printer" and click Next. Your shared printer will appear (firewalls permitting; yes, them again!) and you can select it and click Next. Complete the wizard and you're done.