If I were to have a blog in my classroom, I would use it as an online page to show parents what is going on in our classroom. I would post maybe once a week ( maybe once a month) and discuss what we are going to be learning that week (or month) and what to expect. I would also use it to remind parents of special days, or ask for volunteers. I would use it like a weekly newsletter, but instead it would be online for all parents to view.