The Paleolithic Prescription: A Program of Diet & Exercise and a Design for Living by S. Boyd Eaton, M.D., Marjorie Shostak and Melvin Konner. This book, published in 1988, was the start of the Paleolithic diet movement. Its recommendations are not in line with what today is considered a paleo diet, as whole grain breads and pastas, legumes and some low fat dairy products are allowed. However, it is still a profoundly important book. Used books are available for a reasonable price.
My fiancee and I did this together. It takes teamwork (if you have a family, you probably need to get them on board). It also will help if you can begin (or even complete) this diet when you have a minimum of social obligations--having office mates who eat a lot of cake or friends who drink a lot of booze WILL NOT HELP while you are on this program. Don't try to start this the week before Christmas if your family gathers to eat until they pass out. Be realistic about when you begin this. You must prepare a little bit and read the book ahead of time so you aren't just floating at sea. And, be aware: you will not be able to sufficiently screen foods made by other people!
CrossFit is a strength and conditioning program consisting mainly of a mix of aerobic exercise, calisthenics (body weight exercises), and Olympic weightlifting. CrossFit, Inc. describes its strength and conditioning program as "constantly varied functional movements executed at high intensity across broad time and modal domains," with the stated goal of improving fitness, which it defines as "work capacity across broad time and modal domains." Hour-long classes at affiliated gyms, or "boxes", typically include a warm-up, a skill development segment, the high-intensity "workout of the day" (or WOD), and a period of individual or group stretching. Some gyms also often have a strength-focused movement prior to the WOD. Performance on each WOD is often scored and/or ranked to encourage competition and to track individual progress. Some affiliates offer additional classes, such as Olympic weightlifting, which are not centered around a WOD.