Here is a great blog post with a how to: 

http://blog.lexjet.com/tag/ip-address/ 

Also if you want step by step written:

PC – Connecting to a network with your printer - Connect the printer to your wireless router via an Ethernet cable.  Install driver from usa.canon.com for your printer/operating system.  Follow the install instructions all the way to the finish.  You should get an option to find your printer automatically via Ethernet or wired Lan. If your computer is on the same network it should automatically allow you to register it. 

If the software does not find it automatically, if your printer has changed addresses or lost connectivity… Go to the printer itself and go to the set adjust menu, hit ok.  Then choose “Interface Setup”, then Ok, then TCPIP, then IPV4, then IPV4 mode.  Set that to AUTO and hit ok.  You should see a checkbox next to AUTO.  Hit the back button until it asks you to store the settings , select OK.   Power the printer down with the power button, wait 15 seconds then back on again.  Now go back into the Set adjust menu.   Interface setup, TCPIP , then IPV4 Settings, then choose IP Address.  Write down your IP Address, you will need to use this when you install it.  

Now that you have your IP Address you will go into the start menu of windows (bottom right corner) and search for the Devices and Printers control panel.  Locate the printer driver and right click on the printer. (image below)

Choose Printer Properties and then click on the “Ports” tab.  Click on “Add Port…” then choose “Standard TCP/IP Port”  and click “new port”.   Follow the steps on the wizard to create the port and use the IP Address from the printer.   After you have added the port select “APPLY” in the bottom right corner of the Ports tab.  You should see your ip address on the left with a check box and the printer name on the right. Select ok and you are done!

MAC – If your initial install does not automatically find the printer over your network, locate the IP Address on the printer by going to the printers Set Adjust menu, then Interface setup then  TCPIP , then IPV4 Settings, then choose IP Address.  Write down your IP Address, you will need to use this when you install it.  If it is blank, then go to the IPV4 Mode (hit the back button twice), and set it to AUTO by hitting the ok button on Auto.  Power down the machine and power back on.   On Mac go into your system preferences and delete the old printer out.  Go to your MAC HD à Applications à Canon Utilites.  In that folder find the Imageprograf Printer Setup Program.  This will guide you through establishing the connection to the printer.