I'm doing this now.
I went though three stages of evolution.
First, I had a Sony 200 disc changer connected to a PC via a device called a S-Linke. It took the Sony SLINK signal and converted it to serial so you could control a CD changer ffrom your PC.
Second, I bought an Audiotron. It's a device made by Turtle Beach that plays MP3's from your hard drive, but is a stereo rack component.
Finally, I ditched all of that and went pure HTPC. It is by FAR the best way! Better control, software and sound quality than any other method. No more need for the physical CD's.
There are a few considerations to doing this right. I'll sumarize some of them here, but do some searches and reading on this forum before you buy anything.
PC Hardware: The PC itself doesn't really matter too much for this purpose. Just about anything you buy will be fast and powerful enough to play MP3's. Your real consideration is if you will expand to video later or not. The quietness of the PC is considered important by many. Aluminium cases with large slow fans, or large heatsinks that replace fans produce the least noise for quiet audio listening.
PC Soundcard: There is a lot of controversy over this one. I'm not looking to re-hash any of it here. I'll just sumazrize what I think the general consesus seems to be on this forum:
A: Generally, built in motherboard sound is not the best.
B: Many think that a sound card that supports bit perfect playback is best. Do a search on "kmixer steaming" and read the M-Audio Kernel streaming FAQ thread. If you want to avoid Windows messing with your sound, this is the only option. This rules out all Creative Labs sound cards.
C: People are split over making a Digital COAX or Digital OPTICAL connection between their PC and their receiver. COAX has less conversions and should be slightly better. OPTICAL makes no electrical connection between the PC and the receiver. Some (including me) fear the possibility of a surge from the PC or sound card coudl travel to your expensive audio receiver or preamp. Some sound cards are very cheap and don't instill confidencein this regard!
Audio ripping method:
This arguably could be your most important consideration. First your CD is ripped to the hard drive as a WAV file. Exact Audio copy is considered best by just about everyone. There are then 3 ways you could save the data on the HD permanently. You could leave them as WAV's which would take around 600MB per CD. You could save them in a lossless format such as Monkey Audio's .APE format, which cuts them down 1/2 size. This has the advantage of letting you put them back as exact WAV files later, but still takes a TON of hard drive space. Third are lossy formats such as MP3, which do discard some audio data. They roughly are 15% of the size of the original CD, so a typical album saves to the hard drive as 90ish MB. If you do make MP3's the encoder that converts them from WAV to MP3 is important. LAME 3.90.2 is considered the best here by just about everyone.
Here's what I do, and I am quite happy with my setup:
I have an Intel 875PBZ 2.6GHz P4system with no built in sound card.
I installed a Delta Dio 2496 sound card, with optical/coax digital in and out, connected to my receiver via TOSLINK digial optical cable.
I run Exact Audio copy to rip CD's to WAV files.
I compress them to MP3 with LAME 3.90.2. I do not keep the WAVs.
I play them with FOOBAR with kernel streaming bit perfect playback.
Perhaps some of these steps are overkill, and you can read the "discussions" on this forum and decide for yourself.
Hope this helps,
Andy