Three little kittens need our help

Recently, three little kittens decided they liked my back yard. It is their home now and it looks like I'm their mother. And as a mother I must take care of them. I want to get them vaccinated and eventually castrated/sterilised. I will provide them with food and shelter as I am the chosen one obviously, but I need financial help. I don't have a steady job, I'm a student so every help is appreciated. Thank you very much, kind people!