wedding photography - urgent help and tips?

[itsmeee]

my friend's mum has volunteered me (without asking me) to be the photographer at my friend's wedding in 2 months. The basis of her decision was that i am the only one she knows with a "fancy camera" (Nikon D40) and assumed i know what i am doing.
WRONG! I am still taking photography classes and only been doing so for about 7months. I understand about ISO, Apertures lenses etc but i have never photographed a wedding before.
Despite my best efforts i can't get out of this obligation bestowed upon me so my only choice is to learn how to photograph weddings (or do enough to wing it) in 2months. I don't think i'll need to do the formal shots, just ones where the bride is preparing, getting to the church, some ones of people eating cake etc and possibly a few group photos outside the church.
Anyone PLEASE have links to websites, tips or a prayer to help me out?
Thanks!