"The First 20 Minutes" by Gretchen Reynolds

I've only been exercising regularly for 2 months and had a LOT of questions like this:

-should I use higher weights and do fewer repetitions on the weight machines, or lower weights and more reps per set?
-what type of shoe is best for my fast walking on the treadmill
-what is the minimum amount of exercise I need to get each week to have a healthy heart?

I picked up this book, subtitle is "Surprising science reveals how we can exercise better, train smarter, live longer"

The title is rather cheesy but it is an excellent book. The author interviewed scientists (with degrees in physiology, biology, neurology, etc), read scientific studies, and covers all the major subjects (that I can think of) about fitness - stretching, walking, running, shoes, core strength, what to eat and drink to recover, carb loading, fluid intake, endurance, etc.

For me the critical components of my "get healthy" plan are:
1-a gym so I will exercise without regard to the weather AND so I can track my progress using the machines (miles per hour, time, incline on the treadmill, pounds on the weight machines)
2-playlist of rock and roll on my phone that helps me push myself harder
3-heart rate monitor so I know when I"m in my target heart rate range AND get an accurate calorie count
4-my fitnesspal food & exercise diary - I am a PURPOSEFUL eater now that I input everything I eat into my food diary and must stay under or at my calorie goal. Plus, days I go to the gym I get "rewarded" by an increase in the number of calories I can eat that day.