I've been all over the place on this during this lifetime and have finally settled on a fairly nice blend.

There is a lot of attention being placed on what not to eat.. this is a very healthy trend for so many reasons! Processed foods, concentrated sweeteners, artificial sweeteners, vegetable oils (essentially all vegetable oils are made rancid by the processing) and a plethora of chemical concoctions that have been added to our foods that burden our bodies with a heavy toxic load. And grains... take a serious look at eliminating grains... this is a link to the best reads on this subject that I've found so far:
http://www.marksdailyapple.com/why-grains-are-unhealthy/

But there's also a strong trend among health promoters as of late to focus less on what not to do and more on adding the ingredients that are truly beneficial and more highly preferred. The strategy to this is pretty good... that as we're adding more quality foods to our menu then the nasty stuff will slowly be displaced as the body comes to crave this more richer exposure.

Whole foods, organic, as nutrient rich and as clean as you can find it. There's a strong move toward fermented foods, a traditional mainstay in many vibrant traditional cultures. Homemade yogurts, kefir, and fermented veggies, go a long way toward helping establish a balanced population of our essential gut flora. This emphasis on homemade is important... the commercial versions are often heavily compromised in so many ways! I have a thread going on how to make homemade kefir here:
http://www.spiritualforums.com/vb/showthread.php?t=35951

And as diets to recommend, my wife and I have adopted both the Gap's diet and Weston Price diets as a rough guide to go by. I've seriously tried vegetarianism and the vegan approach over the years and am much much happier with the results of strategically adding a moderate exposure to animal products.

And then there's the supplements... something that my wife and I are still exploring with a gentle touch... we're not diving into supplementation, just sipping along the way... my big find most recently is a good source of magnesium... the importance of magnesium is detailed in this interview with Dr Carolyn Dean: http://itsrainmakingtime.com/2011/carolyndean/ and her website here: http://drcarolyndean.com/
While the best source for highly absorbable magnesium is this interesting discovery: http://www.healthshop101.com/magnesium.html

This is all a quick drive-by, but it helps to outline some of the more solid steps that you could take when exploring this serious study of physical well-being!