I want 10 or more people to do a humanitarian work for me (no salary).
The work consists of a routine of getting information from internet,
typing, editing emails and send emails to hosting companies on the
internet, reply to emails. The complete work flow is as follows:
http://ponziscams.com/smf/index.php/topic,107.msg460.html#msg460
Training will be provided.

What should I do to recruit volunteers on the internet willing to
perform the task for free? I want to spend as little money as possible
in the recruitment.

Ponzi Scams?

You must be joking!

In what way is this "Humanitarian Work"? Apart from the fact you want
volunteers. Who/What are you helping?

kakarukeys-ga,
I see that you are trying to shut down Ponzi Scam web sites. I don't
think humanitarian work is quite the right phrase. Perhaps crime
fighting. Personally, I'm not sure I can help you on how to recruit
volunteers, perhaps another researcher may. A possible source would be
victims who have been sucked into this fraud in the past. Advertise
your forum or web site and appeal for help.
answerfinder-ga

No, I'm not joking!

This project will put an end to the misery of innocent people losing
their money after they "invested" into ponzi schemes on the internet.
This project will also make those who wish to get rich quick by
scamming people on the internet to rethink about their actions. On
this account, may it be called a humanitarian work. On the other hand,
crime fighting is the responsibility of police.

The last suggestion is good. Is there any other suggestion?

Pizza and beer has always worked for me!  (Not kidding)

Just noted the pizza would be cold, and the beer warm by the time it
got to your volunteers' homes, I was too intent on finally being able
to recommend pizza and beer...

Pizza can be reheated in the oven and beer can be put in the fridge.
So it's still a good recommendation!