You should consider the following:
How many guests are attending? Figure out approximately how much time you'll have at each table.
What is the seating arrangement? 60 inch round tables?
Take 3 sets of 3 (A,B, & C) effects and rotate them as you hit each and every table. Also take one or two hard hitting closers for when there is a big group around you during cocktail hour or towards the end of the evening around the bride and groom.
Typically I only hand out business cards at wedding receptions when people ask me for them. At other gigs I pass them out like crazy.
Remember: YOU are NOT to be the center of attention. It's not your special day. You are there to be making sure guests are having fun in the background.
Do not perform during any speeches...please stop and pay attention to the speaker(s).
Typically I perform during cocktail hour, and when other tables are waiting their turn to go through the buffet (if its set up that way). I also make sure to hit the people who are not dancing and just sitting at tables looking bored and are not brave enough to go hit the dance floor. I don't perform while anyone is eating. I will go wait out in the lobby or use the restroom, get a drink, wash hands, etc.
Another tip: Make friends with the photographer/videographer RIGHT away and exchange business cards. Ask them if they could please email you a few nice actions shots of you performing.
I do this every time. If they don't seem like they want to: offer up a free bday party show possibly to them for their kids. Works like a charm and you end up with a handful of promotional photos.
Anything else you want to know?