The first step, is to take a look at everything on your 'shopping' list and find out what charitable options are out there to get your list checked off. You need flowers - why not buy flowers from a charitable fundraiser organization that supplies beautiful arrangments with all profit going to a charity organization. And there's lots of companies out there that sell bottled water that send the money to feed childhood starvation, help villages get clean water, pay for education - there's so many out there to choose from.
Instead of favors to your gifts, make a donation. Instead of gifts to you from guests, ask for them to make a donation. You can give your guests an option as to whom to donate to (have 4 or 5 charities you can work with), or make your whole wedding and opportunity to raise money for one organization.
If you can't find a company that sells, for example, wedding cakes that benefit a charity, why not ask your baker if they would donate a percentage of their profit to charity? Heck, ask all the vendors you're working with if they would make a 5% donation from your purchase to a charity! It doesn't hurt to ask, and you'll be surprised at how many people are willing to help.
{Rebekah} Love of Charity: Giving the Gift of Love - by bekahross on Polyvore.com