ok first off you need to raw his half circle eyes and long nose. Then draw his lip and three half circle teeth. Next his arms (I didn't include the mug but draw it if you like) Barney's arms are long and go down past his shirt. then draw his "V" neck shirt and collar.
Now you need to draw his pants and shoes. His legs aren't very long but aren't fat. And his shoes are just regular blue sneakers.
Now all you need to draw are the stipes on his shoes and wild hair. Also his chest hair which are just twirls. And don't forget the belly button!