At the very bottom of each blog entry, there is a comment form for the blog. Typing into this form will post your comment as a reply to the blog itself.
Before posting a comment, read the entire blog to make sure that your comment is relevant to the blog. A one or two word post does nothing to add to the discussion on the blog and is not adequate to state an opinion. Writing a few sentences stating your views on the blog will help other bloggers understand where you stand on certain issues without being vague in your response.
If a comment is longer than a few paragraphs, however, it should probably be posted as a blog instead of a comment. Comments should address an argument, challenge the argument with a differing viewpoint, and offer some insight into your opinion. You should support you opinion with facts, quotes, logic, or an expert's opinion.
