You can either upload them to your hosting directory (look under the services link on the front page), and then use the [ img ] tags (look to the left of where you post, you'll see a box that says vB Code [help], click on help, and it'll explain how to use the tags). You can do up to 8 images using the tags.
Or, you can attach an image like you would with an email, but clicking on the "Browse..." button below where you type, and browsing to the file, wherever it's located on your computer. You can only do 1 image at a time that way though.
Graphic Design / Photography / Web Design