How to wirelessly stream iTunes to your stereo using AirPort Express
If you already have a wireless-network setup and are looking for a simple way to wirelessly stream iTunes music from your Windows or Mac computer to a stereo or a set of speakers in another room, Apple's AirPort Express is a good option.
Before doing anything else, make sure you have the latest version of iTunes. If not, install the free iTunes software on your Mac or PC. Next, plug the AirPort Express into an electrical socket within a few feet of your home stereo or a set of powered speakers.
Now you're ready to run the setup program from the CD-ROM included with the AirPort Express, called AirPort Express Assistant. When you run AirPort Express Assistant, the program will walk you through instructions on how to link the AirPort Express into your existing wireless network and install Apple's AirTunes wireless-streaming software.
Once you're set up on your PC or Mac with the right software, you're ready to connect the AirPort Express to your stereo or speakers. You'll need a simple analog minijack-to-stereo RCA audio cable. Alternately, you can use a digital optical audio cable if you purchase Apple's optional AirPort Express Stereo Connection kit, which contains both analog and digital cables.
Plug the minijack end of the cable into the open minijack port on the AirPort Express. The jack looks like a standard headphone jack on any portable-audio device. Now plug the red and white ends of the cable into the corresponding jacks on the back of your stereo. Set your stereo to the appropriate input. For this illustration, we are using the CD input, but you can use any that are available.
To start streaming, launch iTunes. Within iTunes, you'll now have the option to stream music through your computer's speakers or to a room where an AirPort Express is installed. From the drop-down menu, select the appropriate room. You can set up multiple AirPort Expresses in multiple rooms, but AirTunes streams to only one room at a time. That's all there is to it.