Now punctuating dialogue is a bit tricky. First of all, you never let two characters talk in the same paragraph. Commas and other punctuation go inside the quotes. And you must paragraph each time a new person speaks.
Finally, Everything a person says at one time (even if they change the subject) goes in the same paragraph. This is pretty simplified, and quotation marks in the US are " at the beginning and end of what is said, but in the UK it's single ' -- so if you're submitting to a UK publisher, US authors remember to change your punctuation preferences.
Final print galleys are out to Elena Bowman for TIME-RIFT.
And ebook galleys are out to Terry Piper for OZARK WOMAN.
And to Kat Brooks, for A KISS OF NIGHT.