Awesome site for Blogging - things to remember when teaching students how to respond. There is even a pdf file available that the teacher has created. On this paper, students are given sample blog responses and discuss whole class whether they would approve the comment.
I wish I would have seen this post yesterday. I had to reteach blogging to our book club group. Mainly, I feel the time constraint/computer issues we had the first two weeks set us back. However, I did something similar to this actually handwriting responses on the white board. The number of posts and details within the post increased dramatically.
My students created this voicethread to go along with the story "The Christmas Pony". Students can comment on each of these pages and it can be used in a self-guided reading group.