Theres a million tips flying around on proper nutrition everywhere you look. is there one good, reliable book or source on this information?

There are so many: Oh, my -- there are so many good books on nutrition available. Some focus on particular health issues, like dr. Mark hyman's "the blood sugar solution" (you don't have to buy all the supplements he mentions). A solid all-around one is "nourishing traditions" by sally fallon and mary enig phd -- it's a cookbook as well as full of nutritional info. "eat drink & be healthy" by dr. Walter willett.

Nutrition Source: I think the book that explains well how your body works, and how food is metabolized in the body is You the Owners Manual by Roizen and Oz (disclaimer: I wrote the recipes). The most reliable data source about what is in food is the USDA http://fnic.nal.usda.gov/food-composition/usda-nutrient-data-laboratory Our book about how food works in the body is ChefMD's Big Book of Culinary Medicine.