Hi Brad,
sorry for the delayed answer.
Yes, that distorted Quad is fine as long as you are aware of it and the (subdivided) result looks good (which it does in your case).
Poly modeling organic shapes like this is not done a lot anymore (usually it is done by Sculpting and then Retopologizing, but there are some older CGCookie Classics, for instance this series Female Character Modeling (12 parts (unfinished but full of rtimeless topology trcks)) starting with https://www.youtube.com/watch?v=g8qbY70F8po
and Edge Modeling a Human Head (3 parts), starting : https://www.youtube.com/watch?v=pHYKLFBNeaM
