Well, they obviously need food, clothing, and shelter to survive. Maybe have a clothing drive and include camping equipment in that.
If you are looking for solutions to help them become employed and self-sufficient. Really, a huge hurdle for the homeless is finding a job without a telephone number or physical address. I’m not really sure how you can help with that but you could brainstorm and see if you can think of anything. Maybe your church could get a separate phone line and start a voice-mail service so people can stop by and check to see if any prospective employers have called them.
And when you are struggling to find food and a place to sleep looking for a job is a difficult thing to do. You need to be clean with decent clothes. Once you find yourself homeless it is a really tough trench to crawl out of.