I've noticed that my knees are really weak and I need to strengthen them, so does anyone have any exercises that will help?? Thanks!!

Can you elaborate on how you have come to the conclusion that your knees are weak? If you can tell us what you are having trouble with than we will be able to help you much better.

Knee weaknesses are normally just a symptom of other things going wrong, you could be pronating your ankles or rotating your pelvis, the pelvis could also be elevated on one side, all of these are normal issues to cause knee problems.

I would suggest that you get a postural analysis done.