I know this is on an Apple forum but . . .
I have just discovered that you don't even need Bonjour to print!
If your printer is plugged in via a USB connection to your Airport then just go to this site and follow these steps.
http://tech.ifelix.net/1004.html
Yes - I know it says it's for XP but I have just done on both a Windows 7 and Windows 8 laptop.
Read carefully and follow the instructions - don't just follow the pictures - and it will work like a dream.
I have never been able to get Bonjour working on Win 8 although it was working on Win 7 until last week when I installed all the lastest updates and then . . . ZILCH! Prints would spool but not print.
This method is quicker for printer too rather than using Bonjour.