I am a huge fan of Lucy Calkins and have taken three courses that explored her Readers/Writer's Workshop principles and I've been doing WW and RW for about five years now. I recently reviewed her latest CCSS materials and our school purchased them as they were fantastic.
I'm not making any money on this Powerpoint, I just did a PD (Professional Development) for my school on the elements of WW (I did a mini-lesson which is not included) but it was more background information on what the purpose