Laura - Good video. Some things I would stress are important when blogging and trying to buid community:
Read and comment on other blogs in your niche. Read the WHOLE post and write a thoughful comment. People will see that you know what you are talking about and visit your site after reading your comments.
Respond to comments on your blog. The blog post should be the beginning of the conversation, and comments allow the readers to respond. With a good community you can get real value from comments.