When you are writing a blog, you need to break up large blocks of text so that it is easier to read. I know for myself, when I click on a blog that seems to be all text, I am really likely to click away.It is just human nature to want to have the information broken up. You can do that in several ways, and one of the most popular is to add images to your picture. As you can see, this is turning into a big block of text, and I am going to soon practice what I am preaching, but I want to demonstrate what I am talking about, thus quite a bit of unnbroken text that is getting monotonous.
You can break up text with punctuation, subheadings, ordered and unordered lists, images, movies etc. Depending on the formating you can often choose to wrap the text around the image. I have made a short video that demonstrates how easy it is to add an image to your WordPress blog. I hope it helps.