first choice:
brikis' second link, all the way.
second choice:
http://www.performanceworkouts.com/exercise/kneelinghipstretch.mov
except with some modifications...
- do the stretch with your leg resting on a taller flat surface to minimize flexion of the hip with which you're stabilizing (kinda defeats the purpose of stretching your hips whenever you go right back into full contraction trying to stretch out the other hip), like a table or a bed or something.
- maintain a straight back with your hands on your hips... as soon as you feel your body start to torque or you start to bend over at the waist or low back, stop.
- contract flexion of the stretched out hip into the table for 8 seconds, relax, and move the stabilizing leg forward an inch or two.
- repeat 3x for each leg
third choice:
the first link brikis gave you
as for the it band, a foam roll is great.
http://www.youtube.com/watch?v=c9aJtO0VCqw