I just started an authority blog, and I was wondering how important it is to post images in my posts since my subject matter isn't really one I can post a lot of unique images of. I have feature images on all my posts however, but should I be posting random images within the posts? Also, I plan on making some videos to put in my posts too, this helps the SEO correct? Do youtube videos need to be unique content as well or can I use other people videos? Would it be better to create my own?