Doing Atkins for a month is just nuts, even for those who think Atkins is God's gift.
I say don't do it at all but if you DO do it, then plan on being on it for a year or more. Otherwise you will be looking at yet another yo-yo phase where you wind up weighing more than when you started.
As bluej said: 14 days of less than 20 grams carbs a day, including a total of 3 serviings salad or very low carb veg. All the eggs and meat you want...but only til you are full (never figured out what that meant
Then add 6 grams of carbs for <26 grams the third week and 6 more the fourth for a daily total of <32 grams.
No more than 4 ounces of cheese (newer books) and limit cream to couple tsps. (again, newer editions.)
Diet soda, Diet jello, Diet (no-cal) ANYTHING is fine in any quantity.
That's really all you need to know.
But DON'T even start if only for a month.
Personally, I think the diet is the most unhealthy one ever to gain popularity.