Faces are my favorite part of drawing characters. My absolute favorite part.
I was going to go into how different features indicate gender, race and age but I didn't want to over load with this page. Plus, doing something like that would take a very long time, so I'm going to leave it for another tutorial (that and there are some amazing tutorials out there already for that kind of thing).
I really hope some of what I put here makes sense.
If you want to see some of the design elements I've talked about here just look up some Disney movies, seriously, you will get the same shapes used over and over for the heroine, hero and villain. The characters you are supposed to empathise with will be smooth and round, the villains pointed and triangular and the father/well meaning blocky character square shaped. (Though sometimes the hero will be made up of both square and circular shapes to reinforce masculinity).