For more visual check out Yoga Anatomy, it's fantastic and really shows you what muscles are supposed to be used and engaged.
Since this is an article for beginners, it would be very helpful to have more photos. My brain learns better visually. Additionally, if someone has not had the body experience of what you are describing, it would be easy to misalign without visual cues.
Thank you for this great article. I've been wanting to do inverted poses, but I don't I have the strength and courage to have my heels over my head.
I have been searching the answer for where and how to begin yoga practice.