If you do photography and provide your own images, remember to focus on creativity. Blogs that have images that look overly-commercial tend to repel readers. Take shots at unique angles and make use of some simple and free photo editors; even the image editor on Instagram would do. Quality over quantity. You don't need a supporting image for every part of your blog you write about. Too many photos can be bad, and too few with low resolution is even worst. Make sure your images should be at least 400 pixels in width, give or take some 25px as room for borders. Height doesn't really matter, as long as people don't end up scrolling down to see the rest of it. If you need to resize an image, there free services like Gimp and Pixlr for you to use. Sites like Tumblr will let you reblog great photos and talk about them. This not only gets you a great image on your page, it also increases your chances of connecting with another blogger, opening up doors for many other blog marketing possibilities. For other social media sites like Facebook, Instagram, Twitter, and Pinterest, you can share the photo itself and then include a link to your blog post. Above all else, you must remember to make sure that you have the rights to use and share an image. Read the license guidelines carefully and make use of high quality copyrighted images for your site.