Actually I could have titled this, "A Practical Guide to Actually Memorizing Anatomy"
The problem with leafing through anatomy books is that I get the impression I am learning more than perhaps I really am. I think I've learned something, but when I go to apply it later, it all seems so vague.
For me, a systematic approach and plenty of repetition are what help me really learn the details.
The poser skeleton is not perfect, but it's not too bad. I like to render it in different positions and print the skeleton poses onto work sheets. For each pose, I find a muscle -- the deltoid, say -- and I draw it in position onto every skeleton worksheet I have.
When you have to really place it, you have to take the time to see exactly where on the clavicle the anterior head goes, and exactly where on the scapula the rest of it goes.
Same with the rhomboids. Here as well, you have to see from just which edges of the scapula they come, and just how high on the spine they go.
Why do all this?
If you know and can draw a skeleton, and if you know and can place the muscles, you'll have gone a long way toward drawing complex, well realized figures from nothing more than your imagination. And regardless of how important life drawing may be -- it's a fun thing to be able to do without reference now and again.