You asked for it
Ok, basically the Paleo or Caveman diet is based on the idea that humans evolved as a hunter gatherer species with an appropriate digestive system. The rise of agriculture introduced a number of foods that the human body can digest, but which are not optimally beneficial. There is a great deal of additional reading you can do, and if you are considering changing the way you eat you should definitely read everything you can to better inform yourself. However, I'll lay out the basics here.
Essentially you want to restrict your eating to lean meats and fish, fruit, nuts and seeds, and most vegetables. That's it.
What you want to avoid are salt and sugar and foods that contain them. Starchy tubers (potatoes, yams, etc), grains and cereals (wheat, corn, rice etc), dairy and legumes (peas, beans, lentils, soy peanuts etc).
So say goodbye to french fries, pasta, cheese, milk and peanut butter. Say hello to juicy steaks, big salads or roasted vegetables and heaps of delicious fruit.
I've got a couple links to online resources you can check out for more information.
http://www.earth360.com/diet_paleodiet_balzer.html
http://altmed.creighton.edu/Paleodiet/Foodlist.html
As well as a link to the book that I picked up that includes all sorts of information regarding why the diet works, and the health benefits it imparts, as well as the reasons for avoiding the foods that it does. The book also includes a sample meal plan and recipes that make starting out super easy.
http://www.amazon.com/Paleo-Diet-Wei...2011425&sr=8-1
The books suggests easing your way into the plan in different stages and allows you to have up to 3 "cheat" meals a week and still reap the benefits of the diet. I usually limit myself to one cheat meal a week (ok, ok, sometimes two), but for the most part I find it incredibly easy not to cheat. I have no cravings for salty or sweet treats anymore. I see a doughnut and cannot even imagine eating it anymore.
It may seem overwhelming at first to remove the grains and cereals and potatoes that make up so much of a North American diet, but I love to discover new vegetables, and spices and ways of preparing them. I'm eating better than ever before. I tell people that I'm eating huge meals all the time, but there is no sense of lethargy after eating.
I know that it may not be for everyone, but I would definitely recommend it to everyone to try for a few weeks and see how you feel. Disregard any immediate weight loss, and just see how you feel eating that way. I suspect that you would see a weight loss as well, but I don't want to make any promises