Bulbapedia has a great Natures and Characteristics page should look there.
The IV Calculator us fairly easy to use just put in your nature, characteristic, level, and stats then hit calculate. If it says encountered an error so-and-so stat should be this amount subtract the difference of what you have and what it should be.
My team is home to all IV31s as you saw pages back my Shuckle with perfect DEF. At 100 it will be at 614 which is redonkulous.
I also have a perfect Chandelure :) all those hours of breeding, EV training, petting and head butting yarn balls is paying off.