Welcome Stephen,
The modern Paleolithic diet is not meant to exactly replicate what our ancestors ate which varied with season and geography. Instead, it is meant to take the general concepts and apply them to our modern food supply as best we can to restore optimal human health and reverse the epidemic of chronic diseases that have plagued humans since the agricultural revolution. Essentially, it is a diet focused on consuming whole, fresh, natural unprocessed real foods, such as meats, eggs, fish, vegetables, fruits, nuts and healthy fats. It eliminates the top three food toxins –sugar, gluten, and processed seed or vegetable oils, making it an anti-inflammatory diet. You eat foods that are nutrient dense, with many naturally occurring vitamins, minerals and protein, over foods that have less nutrition. Vegetables are an important part of a real foods lifestyle, but no hunter-gather society was exclusively vegetarian. It’s not a low calorie “diet" either-- you eat as much as needed to maintain strength, energy and a healthy weight. Fat isn’t the enemy -- it’s a great energy source when it comes from high quality foods like avocado, coconut, grass-fed butter and meats, fish, olives, and nuts.
Here is a one page description that captures the highlights and some of the options (e.g. maybe add dairy later if tolerated) :
http://www.rubiesandradishes.com/paleo-basics/
Mark Sisson's Primal Blueprint book and blog is one of the first popular resources for Paleo and still my favorite. His 21 day transformation book is a shorter "how to" guide, good if you want to dive in and need direction. Good pointers here to get you up and running. Also review his Carb Curve.
http://www.marksdailyapple.com/pres.../#axzz3VaEMiwuA
You have a challenging goal and I might suggest you stay under the 50g Ketogenic level at least to start. Definitely sign up for his email list and get his Fitness Guide. It has links to videos of him doing many levels from very beginner to very advanced of Many exercises. A great resource for an appropriate exercise routine for you as you progress.
Robb Wolf of The Paleo Solution distills down Paleo even further to a Quick Start guide.
Two Pages..love it!
http://robbwolf.com/wp-content/uplo..._QuickStart.pdf