"I'm just going to have a friend shoot my wedding," - Good Luck!
No offense to you, or your friend, but having a friend shoot your wedding to save a buck is a terrible idea. Just think about it for a minute.. If I shoot your wedding I am bringing 15+ years of wedding photography experience. I have seen 'all the things' and have shot in all situations: sand, rain, snow, heat, on the side of a mountain, all lighting situations, angles and views.
That 'nice' camera that your photographer has is only about 20% of the total equation. You are paying for professional quality work, a person who is a third party to work at your wedding, not just catch a few good moments. My job is to seek out most ALL of those memorable moments while you AND your friends are enjoying yourselves!
What do you wear for engagement or family pictures? I get this question often. I typically tell clients:
coordinate but don't match,
wear something you are comfortable in,
put kids in a color that pops,
something that suits the season,
last but not least, check Pinterest!
Very few of my clients know what to do when they have a session.