Have you heard about Facebook? I'm just kidding. If you're even the least bit "web aware," you know about Facebook. Odds are you have a profile there. Perhaps you've seen friends post links to pages they "like," or you've "liked" the pages of local businesses, television shows, bands, or other things.
Well, you can create a page (or many pages) too. For each blog you've created, consider making a Facebook page devoted to the same theme or topic. When you make a new post to your blog, post a link to it on your Facebook page. Invite your friends (or those you think would be interested) to "like" your Facebook page. Then they'll see updates to your blog, and might click on those links to see what you're doing. They could share with their friends, and random people from around the world will find your Facebook page, and your blog, and your traffic will grow.