You can indeed, thanks to the magic of Bonjour! The only thing I will add is that if it's the new AirPort extreme that you have, you'll need the new AirPort Utility. It's included in Leopard - if you're still on Tiger, you'll need to install it from the CD supplied with the base station.
Also, something you should check (since this sounds like a recent change to your setup)... by default, your AirPort will act as a DHCP server, and it's likely your wired router will too. This can cause no end of problems for all sorts of apps and networking in general, so if this is happening you'd best turn off the DHCP server on the AirPort base station. I made this mistake for a very long time, and to put it bluntly it made port forwarding a royal pain in the a** until I realised what a n00bish mistake I'd made!