To handle submitting forms (such as the login form), you will probably find the HTML::Form module distrubuted with libwww very handy -- it was parse all the HTML and extract the form for you, and provide an easy interface for acting as if you filled in values and clicked the submit button. And for following links with specific text, you will probably need to use HTML::TokeParser and/or HTML::Parser to find their URL.

Note that you will probably need to use LWP::UserAgent and not LWP::Simple since you have to handle forms. (It's not that hard -- makes it easier, too, if you want to add cookie support in the future.)