There are two ways to insert images into your pages. The easier one is to use the page configuration options. This will put a single image at the top of the page in question.
Use Edit page from the Carrelet control panel to edit the appropriate page. Put the image number into the box next to Image at top of page. Choose the correct image library and the required size. Tick Display caption under image? if you want the caption to be visible. Modify the page in the normal way, and the image should appear. To remove the image, set the image number back to 0.