If you take a minute and Google images for “story structure,” you’ll see graphs, triangles, circles, connect-the-dots, etc. All of these methods must have worked for someone, and many of them share very similar elements expressed in different ways. I’m not going to tell you that a certain method must be used to structure your story. That’s for you to experiment with and discover what works for you.
I will tell you that I am a huge fan of Michael Hauge’s Six Stage Plot Structure. You can see the image here, and you can read the application of each stage and the corresponding five turning points for the movies Erin Brockovich and Gladiator here.
If you feel like you’re muddling through your book and you’re not sure how far along your story should be progressing by now, I highly recommend borrowing Michael Hauge’s brilliance to reorient yourself. My friends once pulled me out of line at a writers’ conference to drag me to his workshop with the promise that what he had to say was so good “it will change your life.” I won’t go that far, but if you ever have the opportunity to hear him speak, I emphatically urge you—DO NOT pass it up.