Once you've captured the image (and saved it), the image has to be uploaded to a site that you can link to. Some people use their own web sites, others use a picture storage site like Ripway (see link below). Once the image is stored somewhere (with its own URL), you are ready to use the image in your post.
Click "New Reply" and type your message in the Reply box. Then, click "IMG" (right above the box). You will see a dialog box asking for the link to the image. Copy the URL to the image (from the storage site) and paste it (in the rectangular box in the dialog box). Click OK. Finally, click "Preview Reply" to see if it worked.
http://files.villagephotos.com/signup.asp