Today only, 10/9/2012, Amazon is selling Sketchbook Pro 6 for $28.99. That is over 50% off! I have Sketchbook Pro 2011 and love it! If you already own 2011, there is an upgrade, though it looks like it is not on sale. If I find a sale link, I will let you know.
Check out the software at Amazon. It is very user friendly and easy to figure out!