I wouldn't use a leather shammy from any animal as it may contain natural animal oils.  Buy a few microfibre cloths instead...the kind used for cleaning eyeglasses, but make certain they are true microfiber.  They are available for purchase from many outlets on the Internet as well as nearly every camera shop, as are Rocket Blasters (to blow off your sensor), available from Amazon or other.  Also, consider a lens pen for cleaning your lenses.