Rob,
if you want sparkling wine do not add campden tabs and pot sorbate, it will kill the yeast and stop carbonation, wait til the bubbling stops and its clearing, you can add finings if it isn't clearing on its own, then rack to a clean dj, and prime just like beer and bottle, leave in warm for a week or so to carb up then store somewhere colder
With still wine you either leave it until it stops fermenting and clears on its own, which can take time, or you stop it with campden tab and pot sorb, you need to use them together, used on their own you may be lucky if the yeast is on its last legs but usually it just slows fermentation if used on their own.
