How can I stop them stealing?  

Five words -- it can not be done

Here's why. The page you are looking at belongs to me. Here it is, displayed on your computer.

Let's see. The page and content were on my server and downloaded to your computer and then your browser displayed the page. So, my page and content is actually now saved somewhere on your computer.

There is nothing I can do that will stop you from getting a copy of my code and my pictures on your computer. There they sit, just waiting in your 'temporary Internet files' folder.

     So what can I do?  

The best that you can do is make it difficult for people to copy your pictures or copy your code. And if you're really interested in that 'no right click' stuff and more techniques for making it difficult, then visit continue.to/hope.