I want to set up a small home studio. What should I be looking for in a digital recording system?
I'm most familiar with Windows on a PC, and have been eyeing off products like the Delta 1010LT
Note: I've never used a PCI card, only external hardware....
I hate to say this, but "it depends". What do you want to do? Do you need to record vocals or a full instrument band?
If you're a solo vocalist/podcaster/etc, then you can roll with something like the M-Audio Mobile PRE and a condenser mic (or any other good vocal mic). As for software, you can go with Adobe Audition or Pro Tools or even Audacity.
If you're looking to get into more track recording for various instruments, you'll want software and hardware which can accomodate. So to better help with that you can buy something like the FastTrack (http://www.m-audio.com/products/en_us/FastTrackUltra.html)
If you're into electronic music or software composing you can get a system like Ableton live, and a MidiController such as the Axiom http://www.m-audio.com/index.php?do=products.family&ID=USBkeyboardcontrollers and plug it into Ableton, Then you can record and compose. Then if you need a live instrument you can track it into the software.
So over all, you'll need:
If you can explain what you would like to do with your home studio I think we can help identify what gear you'll need better.