1. Dialogue
How to properly punctuate & accentuate the words your characters speak.

2. Example of non-formatted dialogue
I walked into the room. Mary was there. She asked, “What are you doing?” I said, “I just came in to see if you wanted to start dinner.” “I already ate before I came home.” I said, “Well, will you help me anyway?” “No.” I asked her, “Why not?” She screamed, “Because I already ate! What’s wrong with you?” “Nothing,” I said. “I’m going to leave,” I said. “Fine,” she said, and went back to looking at the TV. I left the room.

3. Things to remember when writing dialogue
Write it as realistically as possible.
Make it clear who is speaking when.
Do not give too much information or unrealistic information in dialogue.
Keep the conversation moving.
Make it as easy to read as possible.

4. Rules of punctuating dialogue
Start a new paragraph when a new person speaks or a large passage of action interrupts the speaking.
Use quotation marks to surround all spoken words on both sides.
Use dialogue tags to show who is talking
Use the proper end marks.
Endmarks always go inside the quotes.

5. Endmarks – possibly the most difficult part of dialogue.
Use a comma if the dialogue is a statement and there is a dialogue tag following. Example: “Welcome home,” she said, stepping forward to take his hand.

6. When a speaker tag interrupts the speech...
Treat it as parenthetical information and use a comma on either side. “I can’t believe,” she said, “that you are finally here.”

7. Use a period...
If no speaker tag follows the quotation: “Welcome home.” She stepped forward to take his hand. “Thank you.” He offered his own hand in return.

8. When a question mark or exclamation point is used...
Follow with a lowercase letter if a speaker tag is being used.
Use a capital if it goes right into action.
“It has been so long!” she exclaimed. “Hasn’t it?” Her hand was warm in his own as he smiled down at her.

9. When only two people are talking, you don’t have to repeatedly say their names
“I understand how you feel, alright?” Jenny asked Tim.
“You do?” He replied.
“You know I do.”
“And do you care about me?”
“Of course I do.”
“So you’ll take the truck back?”
“Over my dead body!”

10. Dialogue Tags
Dialogue tags like “he said,” or “she explained” have two main purposes:
1) Tell the reader who is speaking
2) Show how/why the speaker said the words, or what he/she was feeling

11. Add Variety & Substance
“He said” and “she replied” might be all a story needs to make sense. But adding more interesting dialogue tags creates variety and gives the speaker’s words more meaning.

12. However, don’t overdo it!
Avoid too many “creative” dialogue tags
Some writers become overly creative when it comes to dialogue tags. They seem to think that “said” is boring, so they use a plethora of tags such as whined, admitted, yelled, grumbled, etc. Please don’t do that. “Said” and “asked” (and the occasional “shouted” or “whispered”) are actually the best verbs to use in a dialogue tag.
Readers’ minds skip over it, while other tags pull the readers’ attention away from the dialogue and become a distraction.
Creative dialogue tags are telling not showing. They explain the dialogue to the reader, which can come across as patronizing.

13. Dialogue Tags Don’t use dialogue tags that are physically impossible
Since you can’t laugh, smile, grin, growl, moan, etc. a sentence, please don’t use these words as dialogue tags.
Example: 
Incorrect: “No way,” she laughed.
Correct: “No way.” She laughed.

14. Using adverbs in dialogue tags
Use adverbs in dialogue tags sparingly
Similarly to the use of creative verbs in dialogue tags, adverbs explain the dialogue to the reader, which can come across as patronizing. Instead of telling through adverbs, show us the emotion through the words and the body language.
Example: 
“Give me the hat!” she said angrily.
This line of dialogue could be rewritten into:
She jumped up and clutched the edge of the table. “Give me the damn hat. Now!”

15. Non-Formatted
“Stop!” Buddy said as they approached another intersection. At this one, the light had burned out and a tall oak stood off to one side. “Let me out here.” Are you crazy,” Joe said. “It’s still at least another twenty miles to Mud Bucket! “Just let me out, Joe. I mean it.” Buddy had become desperate. He could think of nothing else he wanted more than to become a famous musician, and if it took selling his soul to the devil to do it, then he would. Joe pulled the truck over onto the gravel at the side of the road and rolled to a stop. “Are you sure about this? It’s freakin’ creepy out there, man.” “I have my phone. I’ll call if something happens.
“Well,” Said Joe. “don’t think I’m coming back out here for your sorry butt,” Buddy got out, slammed the door shut, and Joe spun off onto the highway, his tires screeching on the blacktop.

16. Formatted!
“Stop!” Buddy cried as they approached another intersection. At this one, the light had burned out and a tall oak stood off to one side. “Let me out here.”
“Are you crazy?” Joe inquired. “It’s still at least another twenty miles to Mud Bucket!”
“Just let me out, Joe. I mean it.” Buddy had become desperate. He could think of nothing else he wanted more than to become a famous musician, and if it took selling his soul to the devil to do it, then he would.
Joe pulled the truck over onto the gravel at the side of the road and rolled to a stop. “Are you sure about this? It’s freakin’ creepy out there, man,” Joe muttered.
“I have my phone. I’ll call if something happens,” Buddy replied.
“Well,” whined Joe, “don’t think I’m coming back out here for your sorry butt.” Buddy got out, slammed the door shut, and Joe spun off onto the highway, his tires screeching on the blacktop.