You can use LWP to do it. There is also a package called Mechanize on CPAN you can use. It is a layer over LWP. You may want to get this book http://www.oreilly.com/catalog/perllwp/
. Shop around, it's cheaper on Amazon.
There's even a link with examples. http://examples.oreilly.com/perllwp/
This will grab the html from the google homepage.
$browser = LWP::UserAgent->new() unless $browser;
my $resp = $browser->get('http://www.google.com');