The double crochet is about twice the height of a single crochet. It is a very popular stitch.
Make foundation chain 2 chains more than the number of double crochet stitches called for. Skip first 3 chain stitches (will count as the turning chain).
To begin the second row, turn your work. Chain three for the turning chain (counts as first double crochet). This means you skip the first double crochet below the turning chain.