You need to check out this new site Youth Bloggers Network! It was created by a teen blogger named Patrick D. It is a great site for any teen blogger to promote their blog, get advice and tips or just to chat to other teen bloggers.
Currently there is a forum where members can post about blogging, making money online, and whatever they want. There is also a blog where members can post an article that they think will be helpful. This also can be used to promote your blog because you are allowed to link to your blog in the post. Also you can buy an ad space for a very low fee.
This site is really great. There are some very knowledgeable and talented teens who are members even though the site is very small. Sign up is totally free and very easy. You definitely need to check this site out even if you are not a teen blogger- everyone is welcome.