There are tips on how to make links and images work on this link here.

The trick is to use the markdown button below. Or if you're that sort of person, you can enter HTML directly and select the HTML tab.

Unfortunately, you can't upload photos directly. You can use a free photo account like Flickr or Photobucket and make links from there. Most sites have got an 'embed' code you can use.

For example, look at this video of a friendly chat on the Stroud Green Road. On the middle-right of the page, it says 'embed'. You can copy that code straight into a post, select HTML and it will appear on the site.