Struggling to get LiveUser working

I am trying to use LiveUser for a site I have been working on for months now. I have managed to install LiveUser but I am struggling to understand how to implement it on the site. I have looked at the examples and can't get my head around how to use this class. I am quite new to using PHP coming from an ASP and Perl background. I have managed to use other Pear classes before but this one I am struggling with. I think the class is exactly what I need for this site which is an archive site for mailing lists but requires security at the request of the group. I have tried reading the docs and the examples (I can't get all the examples to work) to see how to get it work. I know that LU does what I want but I can't find an example that will make it easier for me to understand its implementation. Any help or pointers would be gratefully received. Graham