I think it's very important that you read about the diet. It's basically an elimination diet. You will need to go through a detox stage and the book will explain the what/why this happens. I've seen a few posts on another forum stating the diet didn't work for them...but they were eating grains once a week.
If you eat the typical American grain-laden diet, your body is a sugar burner. You will need to give your body a chance to switch over to burning fat for fuel. I'm not going to lie, this stage stinks! You will feel like crap but after 2-3 weeks, the energy will switch on, your food cravings will disappear, and you'll see the difference in the way your clothes fit. I lost scale weight a lot slower than I lost inches.
Mark Sisson was a world class triathlete for several years and he talks about his high grain diet during those years, and what that did to his body. I think he does a great job explaining the what/why to this lifestyle. Mark is 58 and his wife is 56 and both are living examples of how healthy this diet is! I was reading the reviews on Amazon and someone said Mark was married to a woman half his age. LOL He's not, she's 56 but has the body of a 20 something year old.
Anyway, I feel it's important to understand the diet fully. Primal is a bit more relaxed version of Paleo, but it is Paleo.
Dairy is considered a non-Paleo by Dr. Cordain (85/15 rule), but is considered a "grey" area by Mark Sisson. You will need to eliminate dairy at first, and reintroduce it later to see how you respond to it. Many people have problems with dairy. Dr. Cordain believes it leads to cancer.
I eat a small amount of dairy (cheese, fage yogurt) and it doesn't bother me.
Here are some great podcast to listen to-
Rob Wolf and the Author of Wheat Belly-
The Paleo Solution – Episode 95
Podcast