What is your goal with this script? I have written a brief tutorial on using mechanize that can be found here: WWW::Mechanize Basics
I also recommend getting the firebug firefox extension and manually inspecting the page for each thing you want to access. For example, the url for 'Latest News' is
http://www.truro-penwith.ac.uk/category/news/ which I determined by using the firebug extension..
So to go there, just do
my $mech = WWW::Mechanize->new();
worked for me.. you don't need to do anything with headers..