These are raw denim, right? Wash them as little as possible, especially the first time as this lets the fades set in (the longer you wait the better). Obviously, you don't want home smelling funky, so try not to sweat in them, etc. Some hardcore raw denim heads will even use febreeze before washing them.
Once you decide to wash them (6 months minimum waiting period), turn them inside out, soak them in lukewarm water in a bathtub with a little Woolite Dark. Give them a little shake and let them sit for about 30-60 minutes. Empty the tub, rinse with cold water to get the suds off them and hang dry. If you hang them in the sun, there's some talk that they might help with the fades.