u/KingNooBly

As the title says, I am tearing off the 30 year old shingles from my house on my farm and would just like some advice anybody has got from doing roofs. Its a simple a-frame roof nothing turning or bending, no bigger than a 3 car garage really. I know I need a bin and shingles but im not sure if I need plywood on my roof as it is a plank roof. Can I just put plywood on top if the planks? Or just repair what needs repairing and put that weatherproof sheets between the planks and the shingles? Any advice is very appreciated, thanks!