I misread your earlier comment, sorry for the useless response.
The response wasn't useless. If you misread it, you're probably not alone. Now that I replied to your comment, it's easier to understand.
You're probably best off giving now once you understand everything, but you obviously can't just give to the first charity you can find. You have to do enough research that the expected decrease in utility from donating later exactly balances the expected increase from better research.
As of today, GiveWell has two new top charities:
1. Against Malaria Foundation
2. Schistosomiastis Control Initiative
Their previous top charity, Village Reach, no longer has much room for more funding. Which is a good thing: partly through givewell's influence they now have as much money as they can put to good use.