I'm assuming you are looking for your first job. Your best bet really is to pound the pavement - go to the mall, to your local fast food places, and especially to little hole-in-the-wall restaurants. These places are most likely to hire a 16-year-old with little or no work experience. You'll have to fill out an application each place you can, and wait for them to call you. Do the application even if they aren't hiring right now - a week can change that, and then you've got your foot already in the door.

When you go out looking, dress neatly and relatively conservatively - you don't have to look like you are going to an office, but you'll do best if your hair is a natural color (not green or purple or something), you don't have excessive piercings visible, and your clothing isn't revealing, and doesn't say anything offensive. Look people in the eye. Ask if you can fill out an application - do not ask "are you hiring" or "do you hire 16-year-olds". If you carry yourself well, you'll make a good impression, and they might even make an exception (if it's possible to do so).

If that fails, I'd try looking for work mowing lawns, babysitting, or pet-sitting - ask friends of your folks, and folks of your friends, neighbors, relatives, and so forth. Eventually, work will find you.

Almost any fast food place!

Craigslist is a good one. Just be careful, I landed a shitty marketing job that payed commission. Got ten bucks for walking around in the rain for eight hours.

This is what I did to get my first job, I had an older friend help me. He had worked at KFC when he was in high school so he drove me to the place and said, "Hey I used to work here, wanna help a buddy out?" I got an interview and they hired me. Its a shitty job though, hell I thought my first job would be at Hot Topic or a record store but with no experience, I couldnt be picky you ought not be either.