Assalamu alaykum,
I can feel you, it is a surprisingly complex issue and no clear consensus on it.
An opinion I have come across many times is that if you are drawing very cartoon-like and unrealistic pictures of people or animals then it should be okay inshaAllah, particularly if it is for educational purpose. One must exercise caution though, you mustn't make them too realistic - facial features should be very loosely done or exaggerated.
Maybe like this?
This link may help:
http://en.islamtoday.net/artshow-383-3367.htm
Someone can clarify further, and Allah swt knows best.