Treatment and shelves for shed

Just got a 7 x 5 shed T&G.
Its supposed to already be treated but i plan on using some timber care on it outside to match the garden fence. Does this need doing inside the shed too?

Also whats the best method on putting a few shelves up in it?
Just good old timber batterns or is there a better method?

Thanks

no it doesnt (but you can)

depends what you want to put on shleves


i would put plywood up so that:

a) move a shelf no holes in shed

b) put short shleves in if you wnt to

c) put hooks up for tools like shovel, hoe, rake etc