pentax 135mm

Tips for wedding photography?
I was asked to film a marriage by a person who works at the place where the volunteers. I have not shot a wedding before, but I'm studying photography and have extensive experience working in various fields. I a Nikon D80 with 18-135mm lens and a Pentax SLR super me film that could be used to make b & b. Do you have any advice?
Wedding Photography Tutorial: http://www.net-art.it/photomonitor/html/teoria_tecnica/ripresa-tecniche/matrimonio-cerimonia-e.shtml
PENTAX 50-135 SDM