If you are using your own images, just type the name of the file in the box. If your images are in the subdirectory images the path would be images/name.gif notice there is no / before images
If you are using the basic editor and want to add images in the Text area ( block ) do it the same way as the in the advance editor.
<img src="images/name.gif"> if you have the image in subdirectory images
<img src="name.gif"> if you have the image in the same directory of the html file