There is documentation and software to download at the Gtk-Perl homepage
You can download a tarball of the whole site from the tutorial homepage so that you have a Gtk-Perl tutorial/manual for use when you are off-line.
I have learnt a lot from the tutorial and examples and I think that this is the best way to start with Gtk-Perl.
pod2html perl-gtk-ref.pod > perl-gtk-ref.html
pod2html perl-gtk-ds.pod > perl-gtk-ds.html
Online HTML examples of what is produced are
GtkObject
+----GtkWidget
+----GtkContainer
+----GtkBin
+----GtkItem
+----GtkTreeItem
you must get a ref $ti_ref to the TreeItem and then call $ti_ref->add()
rather than gtk_container_add() as you would in C.
The gtk-perl-list grew out of gtk-list@redhat.com and there is still plenty to learn from that list too.
Please don't post long code examples or attachments and definitely no HTML :-) Also use a meaningful subject line, 'How do I add text to a Gtk::List' is much better than 'Help, I'm a newbie'