Here is how Expert Extrusion handles money and links on the site.
Affiliate links
This site does not use affiliate links. The home page says the same thing in short form: no affiliate modules on these pages.
Partnerships
If a paid partnership is ever added, the guide that carries it will say so next to the link, and this page will be updated. That sentence is not a promise that a partnership will happen.
Sources
Guides name the sources behind their numbers so you can check them yourself.