Skelliwag publishes a wide variety of advice for bloggers. This article is one of my favorites:
WordPress.com makes it easy to add photos, size them, float the text around them, etc. Here is the support page, with all the details:
In our class, we will use the “From URL” option, since we are using the church’s computers. But for working at home, I strongly recommend downloading the image to your own computer and then uploading it to your WordPress.com account. That way, if the photographer takes down his page, you will still have your image.
Most important: BE SURE to give credit to the photographer!!! I include the photographer’s online nickname in the caption and make the photo itself link back to his Flickr page.