Jimmy, if your are being sincere and honest about a sizeable donation, I strongly recommend a donation DIRECT TO St Jude's Children's Research Hospital.
Check out their website at
http://www.stjude.org/stjude/v/index.jsp?vgnextoid=f2bfab46cb118010VgnVCM1000000e2015acRCRDYou other GetBiggers might want to check it out too. Any little bit helps.
But please remember that there are many "Fund Risers" who solicit donations for various charities and it's perfectly legal to keep a percentage of those donations in order to keep their fund riser business in operation. So I do recommendation that donations be made direct to any charity of your choice, such as St Jude's.
Not for Profit Corporations are guided by a Federal Publication called 501.3.(C) if I recall correctly and you can find that on the net. Also it is wise to check the net for government guidelines for those who intend to make donations of any size to a charitable organization.
Best of luck to ya, Jimmy.