Example image from Fancy Zoom.

There is not mutch to say…
Select your big and small image.
Enter for the small image the bordersize and bordercolor.(if you like)
Type the text what shows up at the bottom from your image.
Type for every new image a new ID name.
This extension das not work if you enable pngfix.htc in Web Builder.
The pngfix is to show transparentie from png images in IE6 browser windows.

Download for WB 6.5.
http://www.mediafire.com/file/z4zrwjyqm ... _valid.zip
FancyZoom is totally free for your non-commercial website.
In a bit of an experiment: if your website is commercial (i.e. makes you money), you can license FancyZoom for $39 per site, a one-time fee.
http://www.cabel.name/2008/02/fancyzoom-10.html