This is a little tricky and you have to edit the Java Script but it works. You can simply past it into the page you want it on and edit it a little to meet your needs. But it works! http://javascript.internet.com/page-details/no-right-click.html
These require less or no editing.
You can change the background. But be very careful.
1. Go to the style sheet (CSS) in edit fonts.
2, IMPORTANT - copy the HTML that is currently there and save it in NotePad or something. That way you still have the original script in case you mess up.
3. Just under "body" and before "{margin: 0px; " paste this:
{background-image: url(http://the link to your pic.jpg); background-attachment: fixed; }. It must be exact with all the spaces, etc. in the right place.
4. Don't touch anything else.
5. Click on "Update Stylesheet".
If the link to the pic is the right one and you put it in the right place, it should work on all you pages.
If it does not work, paste the HTML you copied (in step 2) back in the style sheet and it will be normal again.