This neck warmer is knit in the round, So double pointed and circular needles are used.
It can be made for a boy or girl.

I have given a web site name where you can go for a tutorial on how to knit with 2 circular needles.

Pattern it self is easy knit and purl stitches.
Depending on how far you knit this one skein of yarn with yardage of about 345 yards should be enough.