Before you jump on the bandwagon of giving things to homeless people, you'll need to know the parameters of what you're doing.
When I was starting out with Project Lovingkindness, I told my dad about it, and he advised me to check on the legal ramifications. Did you know that in some cities, giving food to homeless people is illegal?
I researched and found that if I have a legitimate religious backing for what I'm doing, then I am protected. That means, if I have a religious conviction that can be proven, then I am okay to give food to the homeless. But I only donate pre-packaged food, not anything that I cooked myself (at least not yet!)
Mind you, I didn't start giving my PL Bags only because it was a "good idea". Handing out food to homeless people because it's a "good idea" will land you a ticket or citation. I started this project because I felt as a true Christian, it was my duty to help the poor, and I later found out that my reason was protected under the law.
On the other hand, I do understand why the laws are in place. Everyone out there with a sign in hand isn't homeless. Sometimes they're beggars just looking for handout. Some of the homeless are addicts, and they'll continue hanging around for more handouts. I get it. But it's tough to figure out what to do. Punish everybody for misdeeds of a few? I've chosen to discern who is really in need, and who is a beggar looking for freebies. After you've done this for a while, you'll start to recognize the difference, too.
That's not to say it's not a good idea. It IS a good idea to make prepackaged bags, but unfortunately that isn't enough to keep you from getting cited by police, depending on what area you're in. So my advice to you is to check your local laws.