If you've not already done so, connect your printer to your router, as follows:
If your router has a 'WPS' button, see 'Setting Up Automatically by Pressing a Button (WPS)', starting at the bottom of page 46 here:
http://tinyurl.com/zqfb5ww
(Note the the 'access point' referred to in those instructions simply means your router).
If you've not got a 'WPS' button on your router (or if connecting it that way doesn't seem to work), follow 'Setting up Manually', starting on page 44.
Once you've got your printer connected to your router, print out a Network Status Sheet, using the instructions starting at the bottom of page 53.
The Network Status Sheet will tell you the IP address of your printer. Now return to the link in my earlier post and see if it makes any sense to you!