Some folks who have provided outstanding ideas and inspiration:

Health

Robb Wolf.  Robb Wolf didn’t invent Paleo, but he made it famous. He’s got the gift of gab and a talent for explaining complex physiology in a way that’s entertaining and easy to understand.  Regardless of how you feel about eating like I caveman, I HIGHLY recommend both his book and his PODCAST for developing an understanding of the links between food and health.

Chris Kresser. Chris Kresser has a similar background to Robb Wolf – chronic illness drove him to a deeper understanding of the ties between food and health. Chris Kresser’s email updates are generally long and dense with a ton of good information. I HIGHLY recommend his courses on Pre & Post Natal Nutrition and Heart Disease for developing a strong working knowledge of both subjects. Chris developed both courses as a result of in depth research to address questions from friends and family.

Gary Taubes. Gary Taubes is responsible for leading me down the nutrition rabbit hole. His book Good Calories, Bad Calories is a decade old now but got the ball rolling on the realization that it was sugar, not fat driving most of the chronic health problems in Western society. Gary Taubes and Dr. Peter Attia founded NUSI to conduct independent nutrition research.

Paul and Shou-Ching Jaminet. If you’re looking for specific quantities of macro-nutrients (protein, fat, carbs) and micro-nutrients (vitamins and minerals), Paul and Shou-Ching Jaminet have done the best job I have seen of looking at nutrition from a variety of different angles, identifying the impact of both overconsumption and underconsumption of specific macro and micro nutrients and providing recommendations of specific quantities. Their book is easy to read and contains a wealth of information.

Michael Pollan. Michael Pollan is another journalist who started off with the seemingly simple question of “What should I eat?” He has published a number of books with outstanding insights.

Fitness

Pavel Tsatsouline. Pavel was a physical trainer for the Soviet Special Forces before bringing kettlebells to the United States and training US Special Forces, Military and Law Enforcement (along with thousands of other individuals). Pavel specializes in strength training with minimal equipment. His training background and native language (Russian) provide unique insights from the strength training expertise of the former Soviet Union.

Paul “Coach” Wade. I dismissed Convict Conditioning for years as just another bodyweight exercise book, but eventually bought it after two unsolicited recommendations from two different friends. There’s some debate over whether that’s even his real name but Convict Conditioning and Convict Conditioning 2 provide the best performance foundation I have found. Convict Conditioning has zero to hero progressions (meaning you can start from where ever you’re at and go as far as you’re willing to go

Mark Rippetoe. Mark Rippetoe is a weightlifting specialist with a talent for writing. Starting Strength provides an outstanding foundation for the deadlift, bench press and back squat. Strong Enough and Practical Programming provide outstanding insight into strength training philosophy and programming.

Coach Christopher Sommer. Coach Sommer is a former coach of the US National Gymnastics Team who now runs GymnasticBodies.com. He specializes in developing a strength baseline which will support the dynamic loads encountered in gymnastics.  From Coach Sommer I learned about the importance and timing of strengthening tendons and bones in addition to muscles.