Are you illegally using others' images without realizing it? Stop by this guide to learn the basics of proper image use and citation.
Content that lasts tends to be evergreen (timeless), novel (not yet extensively-covered), and presented with a specific, niche, long-tail title.
Because your articles are public and available for the world to see, there is a chance that someone might copy and republish them. Here's the HubPages guide on what to do if your work is stolen.