First, do not think iWeb at this stage.
Check with your camera supplier if they provide software to display the images on a webpage.
I checked at the Panasonic website, and they have the software, including demos.
If that fails, search for other solutions :
http://www.google.com/search?q=security+camera+web+software
Here's software that works :
http://www.evological.com/
Then when everything works the way you want it, display everything in a HTML Snippet with an <iframe>.
For those interested in using their own cam with live video (picture not included):
http://www.wyodor.net/_Movies/ManualUnicast/UsingQTBR.html