Official sources
Two governments own two halves of this. The province scores you and nominates; only IRCC can grant permanent residence. Nothing on this site is official — where it disagrees with the pages below, they are right and this is wrong.
IRCC
Immigration, Refugees and Citizenship Canada
Owns Express Entry, the CRS, and granting permanent residence. It does not publish provincial points grids.
The provinces
Each nominee program, separately
Publish the points grids scored on this site, and issue the nomination. Every value here is transcribed from these pages.