Paleo diets are based on a simple premise—if the cavemen didn’t eat it, you shouldn’t either. So long to refined sugar, dairy, legumes, and grains (this is pre-agricultural revolution); hello to meat, fish, poultry, fruits, and veggies. What you eat and how much depend on your goals or the specific program you’re on, if you choose to follow one.
You can find most of what you need to know online, but a book makes a handy reference. The Paleo Diet, for example, outlines basic Paleo principles and offers three “levels” that allow for different degrees of cheating—three “open meals” per week on the “entry level” plan, two on “maintenance,” and just one on “maximal.” Depending on the level, you might also get “transitional” condiments (low-fat dressing and salsa) and drinks (coffee, beer, or wine in moderation) to wash down the meat and plants. You can use the levels as you like. Start with the first and move gradually to the more restrictive—or just stay put. For more dramatic changes, head right to the third.