I have a book by Alan Aragon called "Girth Control." It's a really good book. Probably the best I've read for simple stuff that you can implement quickly as far as calculating macronutrients goes.
Alan constantly stresses that in all calculations, you calculate based on your target weight, not your current weight (unless you want to maintain).
I think this is a much more sensible approach to kcal deficit than choosing a percentage to take off.
What do you guys think?