st = stitch
sl st = slip stitch
sc = single crochet
ch = chain stitch
dc = double crochet
sc inc = work 2 sc in one stitch (to increase)
I also start this pattern by using an adjustable (or magic) ring.
This hat is worked in spiral rounds of single crochet, much like amigurumi, so you will not be ending each round with a slip stitch to join to the previous round. For this reason, a stitch marker is very helpful; just make sure to move it up every few rounds to help keep your place.