Dialogue and punctuation

I do a lot of beta reading and critiquing for other writers, and there are a number of common mistakes I see ALL the time.  So I thought I might share a few of them with you so you can check to see if you're making them too.  These are writing mistakes, not story mistakes because nothing drags me out of a story faster than poor mechanics.

Dialogue.  Lots of people seem to have little or no understanding as to how to punctuate dialogue.  So here's a rule to add to your book.  If you're using a dialogue tag (said, asked, screamed), you use a comma at the end of the dialogue, close the quotes and continue the sentence.

Eg:  "It's too far to walk," he whined.

If you follow the dialogue with action, you use a full-stop at the end of the dialogue and the action becomes a new sentence.

Eg: "It's too far to walk." He stopped where he was, stamping his foot against the lumpy paving stones.

It works the same way if you want to put the action ahead of the dialogue too.

Eg: He stopped where he was, stamping his foot against the lumpy paving stones. "It's too far to walk."

And if you want to use a dialogue tag before the dialogue, you use a comma before it.

Eg: He stopped where he was and said, "It's too far to walk."

Easy, right?