Crochet tutorial that teaches you how to Increase (inc) and Decrease (dec) with the Double Crochet. Plus an example on what the increase can be used for.
For written pattern ...
by Hectanooga1 - Crochet, Knitting,
by Maggie Weldon
by Red Heart Yarns
by New Stitch a Day: Knitting and
by Bronislava Slagle
by Nagu's Handwork