Dont tell me the moon is shining...

"Don't tell me the moon is shining; show me the glint of light on broken glass."
- Anton Chekov
Why is dialogue writing so difficult?! Well I find it so. So in my attempt to improve my dialogue I googled- How to write dialogue in a novel. What  google came up with was this:http://www.novel-writing-help.com/writing-dialogue.html
It is a fantastic website for any budding novelist and has given me food for thought for The book Club. I now want to rewrite chunks and point out where exactly I need...