There are so many resources on the warrior poses...they are some of the most commonly seen postures in yoga. You really can't beat Yoga Journal's basic breakdown and how to.
When I first starting doing yoga, I found virabhadrasana II to be kinda boring and also really hard to do at the same time...weird. In the beginning I struggled to hold my arms up without drawing the shoulders into the ears, my thighs burned, blah, blah, blah.
That thigh could totally be parallel to the floor...I just didn't feel like it ok! When you take a wide enough stance to truly bring the thigh parallel to the floor, it becomes a completely different posture and it is a doozy!
YogaGlo teacher and international wonder Noah Maze is quite a stickler on this. This video is great, showing the pose from all angles: