For security and bandwidth reasons, the Go-Photo forum does not allow you to upload images. However, you can display photos on the forum.
Any photo that you wish to display must already exist online. There are many free online storage websites that allow you to store your photos online, and then display them on the forum. Here is a short list of a few of them:
Picasaweb (run by Google)
Flickr
Smugmug
Photobucket
There are many more. Just search the web for “free photo hosting”. Also, most internet service providers give you free space on their servers to use for personal websites or file storage, which you could also use to host your photos.
Once your photos are online, just copy the URL of the image you wish to post, press the “Insert Image” icon
on the forum posting page, and paste the URL into the box. You can configure the look of the image by adding a description, a border or defining the alignment.

By default, your image will be resized to show it within the forum's margins. Clicking on the posted image shows a full-size pop-up.