I did South beach- which is about eating the right carbs (but does start out low carb) and I just followed the books instructions (got a copy with shipping and everything for $4 on amazon).
Basically I've started with cutting out all carbs I can, no bread, pasta, rice, no fruit. I eat lean meats and veggies with cheese for the most part. You can also eat nuts but in moderation (some are higher carb).
I also suggest researching- I feel South Beach is less strict than Atkins.
I know it says only do phase 1 for 2 weeks, but I'm going to keep it up as long as I can.