There sure is. We need to upload them from your computer to the internet.
Step One: Go to a free image hosting site like http://imageshack.us/
Step Two: Hit the "browse" button that's on their main page and navigate to the picture file that you want to upload and select it then hit the "Host It" button back on the imageshack page.
Step Three: It will take you to a page listing various links to the image. You will want to select the, "Direct Link To Image" one. Copy the link it lists there and paste it in between a set of the following tags: [IMG][/IMG]
So it'll look like this:
And once you post, it will show up like this: