From the Knit Picks Website:

Made with a pima cotton and acrylic blend yarn, this hat is super soft! Not too hot as because of the cotton in the yarn, plus the pattern stitches are open so it’s a perfect hat to keep the evening chill off your little one’s head. Make the heart appliqué in several different colors and sew to clips to make it easy to change the look of this to match more than one adorable outfit.

This pattern uses basic stitches – chains, single crochet, half-double crochet, double crochet, treble crochet and slip stitches. There is also a special group cluster stitch (directions below). You don’t need to have extensive experience, but you should be comfortable with working in rounds and with the stitches listed.