On your cache page - there should be a link to "upload images" on the upper right side. Click on this link and it will take to an upload page where you can browse your computer for the image, give it a title and caption and then click the "upload" button.
This will place a link on your cache page to the image in the cache's gallery.
As far as placing an image within the cache's description - you will need to know HTML and the image should be already on the web or able to be accessed from the web.
Good luck and congratulations on your hide.