Regarding Right Use of Speech - samma vaca. Today, I was remembering a dharma talk I heard from Steve Armstrong at a retreat on Right Use of Speech, and it was very powerful.
So, I checked on-line to see if it was available and didn't find it, but I did find another one by Steve Armstrong, that is good. The link is toward the bottom of the page, and opens after you click on it: http://dharmastudyarchive.blogspot.com/
Here is another link with information: http://www.accesstoinsight.org/ptf/dhamma/sacca/sacca4/samma-vaca/index.html
Also, the work of Marshal Rosenberg was helpful in our family. And, like any tool can be misused.
Sharda Rogell gave a very nice talk on Right Speech on a retreat I did long ago. It is something of her specialty, as her degree is in communication, if I remember correctly. I am very grateful for Sharda's kindness, presence, teachings and help as I was coming up in this stuff. She has a great and gentle heart.
This community has been so self-sufficient in some ways, and yet it is easy when there are these great resources here to forget where we came from and the teachers that taught some of those here, as they don't post here and may not even know about this place.
Here is the link to what I believe is a similar talk to that one: http://www.dharmaseed.org/teacher/164/talk/2823/