Typically I start with about bodyweight times 12-13, drop carbs completely, and take it from there. Once your progress begins to slow then lower calories further, but always start high enough to give yourself room for adjustment. The minute amount of carbs that's in a protein shake is fine as long as you're not relying on that for your main source of food. Every 4th or 5th day have a refeed meal if you choose to do low carb, not only does it make things psychologically easier, but in my experience it seems to keep things from stalling.
If your lifestyle is pretty sedentary then I would consider adding in a low intensity form of cardio 3-4x a week, otherwise stick to the weights.