when should you put linseed oil on a bow and what exactly does it do. does it just make it shiny or does it make the bow itself stronger?

is there a type of bow to not put linseed oil on, aside from compound bows

Unless your bow is an entirely wooden self-bow, and is dried out, I can think of no reason to put linseed oil on it. Linseed oil is used to preserve raw wood. Any composite or laminated limbed bow or a bow with a finish on it, won't benefit from it. If you are concerned about waterproofing, use carnuba wax or car wax.

Linseed oil is used to finish gun stocks, it makes them shed water and brings out the grain for a beautiful finish. I finished a gun stock with 20 coats of hand rubbed linseed oil using just my fingertips to apply it. I have never heard of putting it on a bow unless it is an all wood bow and it would be used for the same reason it is used on gun stocks.