I did it as my first job, part-time during A-levels. Well, 3 months anyway! Earned enough to buy my first pair of record decks, than sacked it off the week before Xmas. They were livid, but then they were paying £2.70 an hour (1993, pre-minimum wage) so my guilt was noticably absent!
How would I describe it? Soul-destroying. If you have the intellect for college then you'll most likely be bored to tears. Then again, how desperate are you for the cash? I've done a couple of other bits of shop work and they were far more entertaining...
Oh yeah, the smell, as monkeyspank says. Nasty.