Not a big hint, but put an alias for Print Center on your desktop, and drag and drop files onto the alias.
[robg adds: You can also keep the Print Center icon in the dock if you don't like a cluttered desktop ... I actually get asked this one fairly regularly, as in "what happened to OS 9's Desktop Printing?" While this isn't quite the same (you can't choose the printer, for instance), it's not a bad substitute if you like drag and drop printing and only have one printer.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030617053341315