First, it's great if you have someone to do the diet with. That will help you tremendously. Second, know that your first couple shopping experiences will be more costly than they will be in the future. Third, be sure to strip the house of anything Non-Beach. This was a great move by us and we donated the food to a shelter so it wasn't wasted.
Lastly, don't judge the South Beach Lifestyle by the first two weeks or even the first two months. It gets easier. On the flipside, don't try to cheat early. We had great success by playing it by the book and using the exact menus. It's a lot of initial work, but it does work!