I bought a small program for my PC in April called Finger Print.
It runs in the background and basically allows you to print from your iOS device (I have an iPhone) to your printer. The printer doesn't have to be wi-fi enabled or anything, as the process works through the computer.
It will even print to a PDF (eg, Adobe Reader will open on the screen with the page).
When I bought it, it was US$9.99, but seems to have gone up to $19.95.
Works great for me. When I choose "Print" in an iOS app, my printer shows as available to print to.
http://www.collobos.com/
Disclaimer: I am not involved with the maker of the app in any way, I just thought it might be useful for people to know about.