Best overall advice I've gotten from a book and from a parent:

[lostnfound]

Just picked up the book "How to Talk So Kids Will Listen and Listen So Kids Will Talk" -- looks great. Flipping through it I reached this section that I am definitely going to share it with 'dad', especially the sentence in bold print.

Isn't how you say something to a child just as important as what you say?

It certainly is. The attitude behind your words is as important as the words themselves. The attitude that children thrive upon is one that communicates, "you're basically a lovable capable person. Right now there's a problem that needs attention. Once you're aware of it, you'll probably respond responsibly."

The attitude that defeats children is one that communicates, "You're basically irritating and inept. You're always doing something wrong, and this latest incident is one more proof of your wrongness."

****
from a parent: "Right from the beginning, never do for a child what he/she is capable of doing for himself."

[SoCalDem]

1. We always made it a point to not yell at our kids..

When our obnoxious son would rant and rave at me (when he was a teen), I would wait until he was done, and then say to him in a low and calm voice.. "I'm sorry yuou feel that way..You are entitled to your opinions, and I am to mine.. I am responsible for you, so you will do things our way until you move out.. Shall I help you pack "?..That would usually make him laugh...and then we could sit down and talk..

It's almost impossible to have an argument when the other person refuses to play along.. I am sure it made him mad..that we would not play along, but he survived his "dangerous years"..and surprisingly, so did we :)

[rbnyc]

2. Yes!

Every parent should know and live by this!

EDIT to add: Similarly I always say, if he knew better, he'd do better--this is a teaching opportunity.