Connecting a Mac computer to a wireless network
OS X® Lion 10.7/Mountain Lion 10.8/Mavericks 10.9
Step 1:
Click on the Apple icon, then select the System Preferences… option.
Step 2:
Click Network in the System Preferences window.
Step 3:
Select Wi-Fi and click the Network Name drop-down menu to select a wireless network you want to connect to.
NOTE: If the network security is enabled on the router, enter the password then click Join.
QUICK TIP: Check the Remember this network option if you want your Mac computer to remember the network and automatically connect to it once the computer is in range.
Step 4:
Click Apply.