Where should I start for computer audio??

Audiophile computer audio is just in its infancy, if you ask me. There is not a lot of common knowledge yet. A couple places for you to start learning are:

http://www6.head-fi.org/forums/forumdisplay.php?f=59
http://www.positive-feedback.com/Issue22/nugent.htm

First link is to a head-fi (headphone) forum dedicated to computer-sourced audio. Second link explains why computer audio sounds better than from a CD (if done properly).

There are several questions to figure out for computer based audio:

1. What quality will you encode (rip) with, and what format?
2. Is your stereo system further than a cable's distance from your computer.
3. How nice do you want the sound (i.e. how much do you want to spend).

I have my own personal biases. I would go with a lossless compression for sure, if you're going to take the time to do it, do it right once. If you have a Mac, rip with iTunes' Apple Lossless compression, and check the box for error correction, to make sure you get perfect reads from your CD's.

Squeezebox is a great solution if you need to connect wirelessly. Personally, I am going to buy a usb source (sold from either www.redwineaudio.com or www.empiricalaudio.com - there aren't many commercial products offered yet, it's mostly the modifiers building these right now). I will then feed that source through a DAC. Because a usb source can use a good clock and run from battery power (in the case of the ones I linked to), it can provide a really nice stream of audio. Basically, my understanding is you can spend $1000 (usb source and dac, say), and get something that will best a multi-thousand dollar CD player. Nice.

Of course, if you don't need super-high end, your solution can be as simple as adding a nice sound card with a good analog or digital out (if you don't mind noise added from the computer). I have heard Macs audio outputs are pretty good. My big advice would be make sure you do the data part right (encoding your CD's). You can always upgrade your gear, but I'm almost finished encoding my 500 CD collection, and believe me, I don't want to go back and do it again.

Wanted to add just a bit more. My last post is more of a general answer. For you specifically given the gear you already have, do the following:

1. Install iTunes if you haven't already, and encode your music.
2. Stream your music from iTunes to your Airport Express (you do this directly from iTunes once the Airport Express is configured).
3. Run the Airport Express into your stereo. You have 2 options for doing so. First option (least good) is to get a mini stereo plug to RCA adapter, and plug it into the line in of an amp or reveiver. Second option (best) is to but a mini-toslink (digital) plug, plug that into the Airport Express (it accepts mini stereo and mini toslink), and then plug the other end into the digital input of a receiver (or DAC). That will give you the best sound.

USB out to USB/SPDIF converter (Hagtech, Empirical Audio) to the DAC of your choice: Benchmark, BelCanto. Or just use a USB DAC such as the Brick or Apogee, directly from your computer. Dedicate one of your Macs to audio, get yourself a big hard drive. Rip to an uncompressed or lossless format. You should be set. USB has some distance limitations, but you can get a repeater if you need it. That's all you need.

Some people are interested in using the CD-Rom drive of a computer for a transport because it has very low jitter due to its internal cache and high speed processing.

Albert at space tech lab has been making cdplayers using computer cd-rom drives for years.

Do you live near a Bestbuy?
They have guys who can help you with it.
If not, you can search the yellow pages for a computer advisor.

You should be able get one going in an hour of advice.

Perhaps your wife can set it up for you.

There is a sight called www.listen.com - you can stream from it.

www.classicalarchives.com is for classical music.