Do I need Bonjour on my PC, Windows 7 Professional? I'm hearing alot about iTunes which I don't use. I’m unable to research what Bonjour does. 

If I delete it will it affect anything else on my PC?
In General no you don't need Bonjour at all on a Windows PC and even more so you don't need it if you don't use any Apple Applications like iTunes, iCloud, etc.

If you like to read more about Bonjour or just want to know what it is please take a look at the official Bonjour Documents from Apple.