With a wireless printer, you can print documents on a Mac computer without needing to directly connect to the printer using a USB cable.
1. Install the necessary printer driver from the included CD or from the printer company's website.
2. Open "System Preferences" on your Mac by clicking on the icon in the Dock.
3. Go to the "Print & Fax" control panel underneath the "Hardware" heading.
4. Click on the plus icon on the left side of the control panel window.
5. Go to the "IP" tab at the top of the pop-up window and then select "Internet Protocol IPP" from the list of available protocols.
6. Type in your wireless printer's IP address and queue name.
7. Select the correct printer driver from the "Print Using" drop-down menu.
8. Click the "Add" button to finish setting up the wireless printer. The printer will now show up as an available device the next time you print a document.
source: ehow.com - How to install wireless printer on mac