This is an easy pattern. Circles are easy to crochet in general in simple dc, sc, etc.: just keep increasing groupings one more stitch farther apart for each and every new row and the circle should lay flat even if you keep going like that for forever.
Free Crochet Hooded Scarf Pattern, by Sedruola Maruska. One of five free patterns in 'Free Crochet Accessories Patterns for Crochet Headbands, Leg Warmers, Hooded Scarves and More.' Free registration required at CrochetMe.