Atkins eating plan is a wonderful way to lose weight and sustain it for life. I highly recommend reading the book or going online to the Atkins site and learn how it works and why they have the rules they have.
Induction is very strict, 2 weeks at least with 20net grams of carbs from vegetables and cream. You get the net grams by subtracting the fibre from the carb count. NO sugars of any kind including fruit. Good fats like salmon, olive oil and avocado's. They recommend women eat no more than 1500 calories a day. You will be full from the proteins and fats and so it's easy to stay under that amount.
When you don't eat sugars your body turns to fat for fuel and if you do induction correctly this is when you will go into ketosis. (burning fat for fuel)
As time goes on and you add back in foods that were not allowed on induction you learn to eat for life.
That's a very quick explanation but as I said, get the books, or online, they have very clear lists of acceptable foods and what not to do.
If it is a plant, eat it, if it comes from a plant, don't!