Okay, here. I'm gonna give you a brief tutorial on how to study from an anatomy book. Or any intermediate to advanced drawing book for that matter
1) First, and probably the most obvious is that you actually have to read the book. You'll surprised just how many people pick up a drawing book expecting to just learn from the pictures. You'll be drawing but you won't be learning and processing as fast. (Get a highlighter or notebook to mark or write down any important bits you want to remember.)
2) Apply what you have learned in your own drawings. No it doesn't hurt to draw from the illustrations in the book for a start, but you need to reach a point where you no longer need it as a reference.
3) You absolutely, positively should go to a figure drawing class. This is the perfect opportunity to implement what you learned in a classroom environment, with a real life model to draw. You'll also have an instructor there to give you tips and inspiration when you need it.
In short, The goal is to apply what you are learning from the book and use it in your own work and style. Fundamentals are the key to art proficiency, and is very important to get a grasp of for any artist. I draw cartoons primarily, and I am studying anatomy too. If you have anymore questions, don't hesitate to ask. I'm pretty sure there are some other users besides myself, who are studying art on this board as well. Best of luck.
I'm not an art student, but from my own experience I can say that it helps a lot to focus on one visible body part at a time (e.g. shoulder muscles) and to study all possible positions and movements in detail. I always looked at my own body and my friends bodies in the mirror, and I tried to observe a certain group of muscles from different angles (e.g. What happens to my shoulder when I lift my arm 45 degrees to the side? How does it change when I move if higher? etc.). It's also useful to feel the different muscles (e.g. Which form does the outer shoulder / upper arm muscle, M. deltoideus, assume when I do certain movements? Which parts are hard/soft? Where does it shift to? etc.). This may be tedious, but it'll make it easier for you to predict movements after some time.