I need a guide to the souls of various creatures (i.e. which fill common, lessor, greater, etc gems). I can't seem to find a definitive guide or chart. Thanks.

http://www.uesp.net/wiki/Skyrim:Souls

shadow master: common OR grand? what sort of logic is that.

Leveled, the weaker version you run into at low level is common, the high version is grand.
Look to me that Mammoths are the most reliable source of grand souls at lower level.

shouldn't there be a medium version with greater or have the weaker version be greater?

Thanks!