I think it's an easy drawing for any one..... lets start
1- Draw a circle as usual.
2- Draw that wave ... which will be the upper border of Donald's beak.
3- complete the wave edges to the inside.
4- Draw the rest of the smiling mouth.
5- Draw the lower part of the mouth..... thicken it and draw the tongue.
6- Now you may draw two oval shapes as the eyes.
7- Another two oval shapes as the pupils.
8- Now draw his eyebrows.
9- His well known blue cap.
10- use a black pen to ink your drawing in clean lines.
11- Add some shadows.... and that's it