If you are looking at improving the lives of our poorest citizens I would think that adequate housing would be the most welcome.  I saw a church funded building program to provide single room occupancy apartments to homeless people and to have support services on site.  It was a great thing but took an expensive 8 story building to house.  The cost divided by of the 90 or so tenants was relatively high. With that model there wouldn’t be enough money around to take care of most of the people needing housing.  

I would think that providing a tent for anyone needing one would be a very easy way to take care of people.  They could be set up in shelters and provide a secure space for the residents.   As a next step they could be relocated to nearby land and have decks for the tents to sit on.  They would be interconnected so people could meet other people in the same situation.  If you meet someone and you both want to stay in touch you can tell the system and it will start putting you near each other.  Somehow I am pretty sure that the hope for the most people in this situation is to work together to build their lives back.  So work assignments would be used to get stuff done but also for people to meet and decide if they want to work together in the future. 

The donated money will go a long way.  People will be housed but hopefully they will be put in touch with a new network of folks they can work with and be friends with.

Another tactic is to spend almost no money.  Decide that you want to build adequate housing out of recycled materials that cost you nothing.  A lot of short lumber and small plywood is recycled because it is too small to deal with in standard construction.  But it works really well to build panels that would make up the small tent platforms I was talking about.  Instead of a tent you could have walls and a roof made out of paper mache with a waterproof covering.  Shredded paper is perfect for this and abundant.  There are a lot of materials around that can be used to build shelter for people.  This would take some labor but not much since a lot of it would be mechanized.  I think they could end up looking good too.