Assuming you don't have kegging equipment:
For still brew.
Wait until fermentation is complete, as confirmed with consistent hydrometer readings over a week or so. Stabilize the cider with k-metabisulphite and sorbate. This will prevent any renewed fermentation. Now just adding any sweetener you like, turbinado, table, corn sugar, honey, maple syrup, juice concentrate, fruit juice, whatever. When you have it at your preferred sweetness (I suggest going till it is almost sweet enough, as it blends with age) just bottle as you normally would, no need for priming sugar.
For sweet brew.
Let it ferment completely, then add a nonfermentable sugar to your bottling bucket. This could be stevia, splenda, lactose, etc. Be wary of how much you add, because these tend to vary greatly in sweetness from real sugar. Then go ahead and add your priming sugar to the bottling bucket, and rack your cider into there allowing the sugars to mix. Bottle as per normal.