In Zelda Ocarina of Time in the final battle against Ganon should you save if you die

Saving at any point in the game simply saves your progress and when you start the game up again it will return you to a set point. You might have noticed that if you save in the middle of a dungeon you will start at the beginning of the dungeon again but your progress within that dungeon will have been saved - doors are unlocked, items are still in your inventory, you have the same number of hearts left etc. The same goes for boss fights. If you save in the middle of the Ganondorf fight you will be back at the beginning of the Ganon's Tower again with all your progress up to the point at which you entered the boss chamber still intact.