Click on any image to see it enlarged.

Wrap yarn counter-clockwise around hook once and insert it into BOTH LOOPS of the stitch from row below (or chain stitch for first row).

Wrap yarn counter-clockwise around hook again and draw it through the first loop.

Wrap yarn once counter-clockwise once more, and draw through the last two loops.

Continue in this manner across the row or as pattern suggests.

Double crochet completed looks like this.