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.
"Flat Braid" Square Joining Method for granny squares. Creates a lovely edging! Another method of joining squares, a simple ch 3 interlocking, done as the last rnd on the squares. Join as you go, could not be easier.