I'm new to the exercise world and spent 2 days on youtube to get educated lol. I just decided to purchased a second hand book on amazon: you are your own gym. It has lots of pictures and I could always youtube the exercises to make sure my form is correct. This book is about building muscle with body weight. Still waiting for my book to arrive. I'm going to start very, very slowly. I have extremely weak muscles. I did some push up but couldn't even do two, so I modified it. I'm doing the girls version, crossing my legs. I'm done 4 sets of 5 push ups, with my legs crossed. I be doing it through the day, to build some strength. This is my first day and havn't decided which other exercises to do yet. Let wait for the book and see what happens I'm 42, hopefully I can build some strength .