What is the ruling of Islamic law on an initiative by a group of young people to collect a sum of money monthly and give it to a needy family, and is this deed considered good enough to be continued?

What you are doing by spending is a good deed for which you can hope for a great reward, due to the Almighty's saying: "And whatever thing you spend [in His cause], He will compensate it; and He is the best of providers," and His saying: "Who is it that would loan Allah a goodly loan so He may multiply it for him many times over." The verses and hadiths regarding the virtue of charity and benevolence are numerous, so continue this good work and seek your reward from Allah.