Thanks! As for your question, I say you should draw whatever guide lines you need if they make it easier for you to see the proportions. 
I use to draw the lines that helped me line up the nose, eyes and ears, but after I drew the face a few times it got to where I could eyeball it without the guidelines.
I use to draw the lines that helped me line up the nose, eyes and ears, but after I drew the face a few times it got to where I could eyeball it without the guidelines.