Nichole,

Welcome!

Unless you're doing Tunisian or filet, the stitch is single crochet; however, it's labeled "standard stitch" here because in the UK a single crochet is called a double crochet - we wanted to avoid confusion.

If you're trying to work to a certain gauge, you'll make swatches to find out what hook size gives you the correct gauge with your chosen yarn.

If gauge isn't important to you, then your hook size will depend on the weight of yarn you're using. The hook size shouldn't make the yarn so tight it becomes uncomfortable to work with it.

If not working to gauge, what I generally do in this case is look at the yarn I'm using and then pick my favorite hook for that weight. So if working with a knitting worsted that tends to run on the thicker side, I might use an I or a J hook.

So it's pretty much about what you're trying to accomplish and how critical gauge is for you.

Nichole,

You're so welcome!

Tutts,

Welcome!

I'm sorry to say that HDC is not recommended. The patterns are keyed to a single crochet, which means that using a taller stitch would skew any pattern you make. The only exception would be if your pattern is abstract and elongating it wouldn't matter to you, but otherwise, it's recommended that you use a SC instead.