You can add links by highlighting the text you want the link to be on and then clicking the chain link icon 
on the toolbar
You will then be presented with a pop-up window that asks for details about your link
Enter the reference for the URL into the link field. If you have the full URL simply remove the default http:// text and replace with your reference. If you need to build up the URL e.g. http://www.domain.com/#3# this will also work.
You can use the Title field to add a text description to your link.
Adding an image is now very simple. You just need to click on the 
icon on the template designer menu.
You will then see a pop-up window opening as shown below, just add the reference for the column where the image url is in in the URL field and what ever you want in the ALT field.
If the datafeed only contains the file name of the image you may beed to build up the URL in the URL field for example http://www.domain.com/images/#3#
The Alt Text should be somethign that describes the image such as product title as this is used for text readers to explain what the image is.
A good resource for HTML is http://www.w3schools.com/html/DEFAULT.asp