I wanted to get opinions on the best way to help preserve wood safely. I have some cedar that I'm using to build chicken tractor/coop and thought that linseed oil would help to seal/protect it. Any other suggestions?
Cedar should last a long time without any treatment.
Linseed oil would probably help it too. The boiled linseed oil can actually be boiled, or more commonly "boiled" by chemicals. If you aren't certain which way it is treated, I would use raw linseed oil. It can be diluted with pure gum turpentine for the first coat which allows it to soak in deeper.
Cedar was a wise choice given that it is naturally durable. Especially focus any treatment on the portions of the structure that will be in contact with the ground....you might repaint it with more oil annually or something like that.
One other natural wood-preservation technique is to char the surfaces in a fire until they blacken and begin to "checker" and then quench. The wood is then coated with a layer of comparatively rot-proof charcoal. This treatment supposedly will double the life of an in-ground post of whatever species, as compared with an uncharred post of similar species and size. But your chicken pen might not be made of pieces thick enough to permit this treatment without simply burning them up....
There is a guy on YouTube named logcabinlooms that uses a mixture of linseed oil and pine tar to protect his wooden tool handles and work benches etc. check him out! His finished product looks amazing!!