lol Peter beat me to it.
that's a wicked link. That whole guide to detailing is amazing, and that's only the introduction.
edit: If you want to buy excellent general purpose MFs, check out Costco. they have 20 MFs that are suitable even for buffing (70/30), for 13.99. I use them for pretty much all my work except for final buffing as I have dedicated ones just for that.
and another thing: it says not to expose the towels to hot water. Truth is that you can, but do not put the towels through a whole cycle of hot water. What I normally do is fill a bucket with 3/4 hot, 1/4 cold, let them soak in the bucket with some laundry detergent for a few hours (or minutes if you're in a rush

). Then rinse them out in hot water (you can turn on the cold tap if its too hot for ur hands), and either air dry them, or dry them in the dryer WITHOUT dryer sheets on LOW heat, or no heat (air).
You can further add to the cleaning process by throwing them in the washing machine (delicate or hand washables cycle in warm water) after ur done rinsing them. Wash them seperate from your clothes. During the FINAL rinse cycle, add 1 spoon of vinegar PER towel. The acid in the vinegar will absorb into the fibers and help break up any left over residue that remains.