Crochet Help on Pattern

I found a pattern for a hat that I loved. The hat is a knit ear flap hat. I have been knitting for a few years and decided to make something different. I am making this hat for 4-H and I just got done knitting the hat and found that I had to crochet the bottom of the hat around as the edge of the hat. I don’t really know how to do this at all. I have tried to learn but I really can’t figure this out. Please help me if you can!

This is what the pattern says to do:
With right side facing and crochet hook, attach yarn at center back; ch 1, sc around lower edge of hat, including earflaps, taking care to keep work flat; join with a slip st in first sc. Fasten off.

I have done a video on my website showing how to crochet a border around a knitted piece. You can view it HERE. If you need help with basic crochet stitches, you can check out THIS LIST of video tutorials which might have something you could use.

Hope this helps!

MGM

That really has helped but I have a few more questions.

How should I go crochet into the stockinette stitching on the right side of my hat? I wonder this because the bottom edge of my hat is curling up and I am curious as to how this will affect the crochet edge.