Please keep in mind this piece was written in the throes of anger at someone who made me feel like much less than a real person so don't take the "real person" bit to heart; it was intended as sarcasm but it doesn't seem to come across that way.
I wrote this piece about seven years ago and I think my writing "voice" has changed a great deal but I decided to leave it just as it was on Yahoo Voices where it was hosted for almost seven years starting when the site was still Associated Content. Oddly enough, despite its weird and somewhat failed sarcastic tone, a lot of people read it and some people even claimed they got useful information out of it. So I bit my tongue and squinted my eyes and here it is.
Of course you'd probably want to start with jobs like real people have such as data entry, customer service, retail, sales, cleaning, manufacturing or other traditional jobs. However, you might need to aim for less agreeable occupations such as porta potty cleaner, road kill clean up specialist, or decomp crime scene cleaner. Even for these dirty jobs employers won't hire someone without an address, front teeth, or clean clothes. So, as a homeless person you may need to lower your standards a bit. Or you might just need to try a little bit different set of job hunting and money making strategies.
Try going door-to-door in lower middle class to upper middle class neighborhoods.
Follow your nose - if you smell poop there's probably a yard full of dog crap somewhere nearby. Listen for barking - dog feces usually come from dogs. Approach the stinky yarded home and knock on the door. Offer to pick up all the dog manure in their yard for a few dollars. If they say they have nowhere to put it, offer to bury it in their yard for another few bucks.
After you run out of dog droppings to clean up in your territory look for houses with dirty windows, unkempt lawns, clogged gutters, or yards or porches full of rubbish. Using the same approach knock on the doors of those homes and offer to fix their issue for a few dollars.
Once you've mastered these noble trades you can move onto more genteel occupations.
Find the elderly part of town. Just look for lots of old people. Ask if you can help them carry in groceries when you see them carrying them. Don't ask for payment for this. Then ask if they have any disagreeable tasks such as cleaning the cat box, scrubbing the toilet, taking out garbage, shopping, washing dishes, dusting, cleaning, moving furniture or anything else unpleasant or strenuous they'd rather not do. Offer to do these chores for a few dollars. Old people are great, especially crazy cat ladies. Sometimes you'll find one that offers to feed you and let you clean up. You may even get to sleep on someone's porch or in a garage sometime.
In states that have can and bottle deposit/redemption laws - pick up cans and bottles. Check any cigarette packages you see for money, especially near bars and clubs.
You can also sell what are called "street papers." These publications are created with you in mind. They are a way to earn money with minimal skills. You should be able to find someone selling these in any major city. The instructions for getting some to sell yourself can usually be found inside the paper or a friendly seller might tell you how to do it himself. With many such papers your initial supply is available free of charge.
By all means, please go to your local library to access sites such as Craigslist on the Internet to look for odd jobs or gigs in your geographical region.
To increase the likelihood of being hired at any job interview you need to present as tidy and odor-free an appearance as possible. Do your best to wash up in public restrooms, keep your hair short and brushed, don't drink, and if you are a man - for God's sake shave!
I hope you've found this article helpful. Good luck on your job search!