it's free, they even give you supplies necessary to take care of the kitten.
all you have to to is feed them, care for them & clean up after then for a few weeks.
not sure how to take care of a kitten? humane society silicon valley has a 2-hour orientation & will give you the phone number of someone that will answer your questions.
this article has all the info, including links the the HSSV page & calendar with the next scheduled orientation.
if you're not near this place, check with your local shelter, they might have a foster program of some sort.