How much one should go down while doing squat.. parallel from knee to hips or further take the back part down below the knee..
There is some disagreement on this. Knee pain is a common complaint with squats. Some say that going down further is bad but others say it actually prevents injuring the knees. Try to see what is ok for you.
Either way, a very important step is building up gradually, to polish your form & let your knees get stronger. Our legs can often handle more weight than our knees are ready for.