Mark,
First thing. It is easy...all you need is a little instruction on what to do. You will not fuck anything permanently by trying any of this except by eletrical static The most important thing is to get a wrist grounding device so you do not shock anything and fry it, or touch the computer case or metal frame every 10-20 seconds to discharge excess charge.
What OS are you running? You got onboard sound (sound from your mother board or a seperate soundcard in the PCMCIA slots)? If you have onboard sound (usually in cheaper computers), you gotta disable after you set everthing up with the new card.
Do you have the CD ROM that comes with it? If not grab the latest drivers from M-Audio's website (save them to your drive, make note of where they are). Turn off the computer and plug the card in (make sure the card is seated well in the slot for this is a common mistake of not seating the card properly), after you restart, the computer asks you that it has found a new device, you need to point out where the drivers are to it when it asks (of course you remembered where you DLd them to or point out the CD loaded in your tray if you have that).
When you have done all this, go to control panel and select sound and audio devices. Choose your recording device to be the new AP2496 card. Then use something simple like CDWave to capture (again in options you must specifiy that you are choosing the new AP2496 card to do the recording). You need to tweak with the M-Audio card mixer controller, specify the sample rate, lock clock to audio device and the I/O designation (I forgot how that looks and where it shows up....I just remembered to make a shortcut to my start up tray). If you get sound recorded, it is a start. Once we get there and there are problems like pops and shit, we'll figure all that out when the problem arises.
Just go for it, you are not gonna fuck anything up beyond repair.
ANDY