If you are asking about how to compress the pictures, select one of the
pictures on your Pub file page and the Picture tool bar will pop up. The 4th
icon from the right is the compress pictures tool. Mouseover the icon and it
should say "compress pictures" in the tool tip. (Alternatively Format >
Picture and you will see the Compress button on the Picture tab.) Choose the
appropriate options including a Target Output for the Web.
If you have more questions about Publisher webs, then post in the web group
and we will try to help you there: microsoft.public.publisher.webdesign
Please always include the version of Publisher you are using, the URL of
your site and as much detail as possible.
DavidF