Not as important the first day, but afterward I highly recommend a good pair of knee pads. These are the type I use. http://www.amazon.com/ASICS-ZD360-Super-Sleeve/dp/B005ACKNAK/ref=pd_sim_200_1?ie=UTF8&refRID=14QGB2D94H009RS4M423&dpSrc=sims&dpST=_AC_UL200_SR118%2C200_
I use one of these due to major patellar pain and it works fantastic so far:http://www.amazon.com/ASICS-ZD360-Super-Sleeve/dp/B005ACKNAK/ref=pd_sim_200_4?ie=UTF8&dpID=41lIEOAASFL&dpSrc=sims&preST=_AC_UL160_SR87%2C160_&refRID=0MW22M1QS9B35M9ZJTX0
http://www.amazon.com/ASICS-ZD360-Super-Sleeve/dp/B005ACKNAK These right here. They are worth every single penny. When you're on your knees it feels like a pillow and there's some cushioning on the sides so that you'll still have padding when you're on your side. i 100% recommend this. And I'd recommend getting one for your other knee if you have the money
http://www.amazon.com/ASICS-ZD360-Super-Sleeve/dp/B005ACKNAK This one is good