I'm not very good at this whole mechanics thing, and I usually have my friends do all the work for me... I was able to do my own alternator/serpentine belt install though. It took me much longer than a mechanic would have taken, but atleast I saved several hundred bucks in labor.

I paid $80 to have my alternator rebuilt and $24 for the belt, so in all I paid $100 for a new alternator/belt. It's not that tough to do, just use the how-to article here on CEG.