Very noble cause with the right idea and concept behind it. A few adjustments that i would suggest.
Proof read all your text, there are quite some errors.
Link to the charities that you're donating to and incorporate the links into the content.
Invite the charities to place their links for free, this way people can not just donate but also push the placement of the charities higher in the rankings.
When you donate the first check, make sure that you display an image of the check and eventually a "donation" received statement from the charities.
Get some submitted sites, eventually submitting them yourself. Many users are just going to utilize your services w/o supplying you with sites. If that's the case you're going to lack search results, which is going to drive users elsewhere.
suggestion: start including medical companies, pharmaceutical, and such. after they've been included, let them know about your project. Maybe there are a few $$$ for charity in their pockets.
Not a bad start, beef it up some and the donations will hopefully come.
IB