wget --mirror http://yoursite.com/foo.html will recursively suck down that page and everything under it, including css and image files. See the wget manpage for lots of options.

lynx --dump http://yoursite.com/foo.html may also be useful to you -- by default it provides a list of all the files that are linked to in the rendered page. You could then manually review this or loop over it with LWP::Simple or wget or similar.