Dodecahedron

Reference:  Miyuki Kawamura's book Origami Polyhedron for Beginners
No of units: 12 units 
Paper size used : 5" x 5" 
Difficulty: easy for beginners , easy to assemble and very sturdy model.
Paper used: normal color printer paper
Time: 1.5 to 2 hours

No glue or paper clip used.