It should be covered in the help. It works like this, whenever you create a page with Site Asssist pro, it knows what your content area is on that page. So if you change the content, there is an option available to save that content. Once it is saved, it is available in the wizard. Should be pretty straightforward. Give it a try and let us know if you have any problems.
Just go to Insert->WebAssist->SiteAssist Pro->Create page type once you have created a page you would like to save and make available later.
Did this help? Tips are appreciated...
