Volunteering work in Tanzania, Africa

[foxydivano1]

Hi,

I'd love to go volunteer at a children's charity located in Tanzania - I am over the moon to have been accepted.
Has anyone done this before (anywhere in africa) and what were your experiences?
Which is the best time of year to go?
What do I need to organised etc?

I havent done much research into it yet, but a british family have set up the charity, and its only just opened. I'm helping to raise awareness and funds for the charity, and the founder has invited me to visit and volunteer.
I was thinking of going over sometime next year for about 1 month. Does anyone have any advice?

Thanks