I need to paint the shed floor, What should i use on it? Its a brand new wooden floor by the way.

Yacht varnish ?

i used yacht varnish on mine its still ok after about 6 months i gave it a few coats tho
adam

Second hand steel sheet! stops it burning when welding or angle grinding, easier to find the small bits that fell off the bench, wipe up inevitable oil spills, less aggro if you drop something heavy , like a gearbox, off the bench!

Caber

How about putting some sheets of ply down first to reinforce the floor? floor paint will cover wood OK

carpet if your building your car in there, it will save the knees and will double up as a place to live if you fall out with the missus.