One question that commonly pops up is “Do you really need a picture for a blog?” The answer is no. Imagery is there to enhance your content. Above all the purpose of including an image with your blog should not be to make up for weak content.
Pictures are also more appropriate for certain types of blogs rather than others. For instance a blog about modern art or architecture might require pictures more than a blog about the latest computer chip would.
However there is no reason why the occasional picture can’t be used to augment your writing even if you are using a blog to sell a very dry product such as computer software. The true purpose of an illustration or photograph is to enhance your blog, not detract from it. If the image enhances the point you want to make or is even a well-attuned metaphor for what you are trying to say, then by all means use it.
One problem is that some blog templates are not that friendly when it comes to uploading pictures. In this case it is possible to have the image open in a separate web page so it does not interfere with the layout of your blog. This also gives your reader the choice of whether they want to bother looking at the image or not.
One design rule regarding images is to keep them all the same size. There is nothing that messes up the look of a well designed blog more than having differently sized photographs scattered all over the page. Another problem that you may likely encounter when uploading images onto a blog template is the issue of having to fit the image into a predetermined size. This can mean the image is squished, elongated or stretched laterally. If this is a problem, then don’t bother uploading an image at all.