Images in widget

Can someone please explain how I can get images, i.e. photos in a widget in a sidebar? If I upload an image to my site and 'grab' its URL, all I get is the actual URL text in the widget and the same thing happens if I grab the URL from my Flickr page. If I grab the HTML from the Flickr page, I get part of the picture (too big to fit in the sidebar) and, on clicking on it, it links to my Flickr page which I don't want. Using another template, I simply grabbed the URL from my Flickr page, uploaded it and got a small version in the sidebar. When someone clicked on it, they got a bigger version but not linked to Flickr. I'll happily make another donation if someone can solve this problem that I've spent hours trying to figure out, given that my knowledge is Basic!
Thanks in advance.