Materials:
US size 6 or 7 double pointed needles
Worsted weight yarn in white and black, small amounts of red, green,
and some orange (or a small button) for his nose
Gauge: don't worry about it it doesn't have to fit anybody
Body
With white cast on 21 sts. Join and knit in round for 24 rows.
Break off yarn and use the end to draw up the remaining stitches.
Stuff and then pull up the stitches on the cast on edge. You now have a white pill shaped object. Wrap some yarn around about a third of the way down from the cast on edge to make the "neck". Embroider face and "coal" buttons.
Top Hat
With black cast on 36sts, join round
Rnd 1: [knit 4, k2tog] 6 times (30sts)
Rnd 2: [knit 3, k2tog] 6 times (24sts)
Rnd 3: [knit 2, k2tog] 6 times (18sts)
Switch to contrasting color
Rnds 4-6: knit
Switch back to black
Rnds 7-15: knit
Rnd 16: [knit 1, k2tog] 6 times (12sts)
Rnd 17: [k2tog] 6 times (6sts)
Rnd 17: [k2tog] 3 times (3sts)
Break off yarn and thread through remaining stitches. Tie off, making a loop for hanging. Darn in the ends and sew to snowman's head along the bottom edge of colored band.
Scarf
You could knit your snowman a scarf but I just twist or braid together 3 strands of red and green yarn. Wrap around his neck twice and tie.