By pressing the bottle down on the sprayer, the sanitizing solution is sprayed up into the bottle, leaving it sanitized. Another handy item is the bottling tree, where you hang your freshly sanitized bottles to drain. The tree holds either 45 or 90 bottles. As with yeast, use only fresh pectic enzyme to help break down the pectins that cause your wine to be hazy. An extra benefit of using Pectic Enzyme is an increased yield.
Yeast nutrient is basically urea, though highly purified.
We have a good supply for you at the Brewing Station. Think of it as the yeast's vitamin pill. It is especially important in making mead. Yeast nutrient is cheap and keeps well. For sanitizing, use 18 tablets per pint of water.