The first thing to figure out is what you will enjoy doing. If you are going to be spending a large chunk of your summer vacation working, you should pick something that won't bore you to tears everyday. Check out your favorite stores at the local mall. The places you like to shop often hire young people who are about the same age as their customers.
Most organizations look for people who take initiative.
So if you are interested in working somewhere in particular it never hurts to give them a call to see if they are planning to hire soon. The worst thing they can say is no. There is an endless list possibilities if you are willing to get out and explore your interests and what your community has to offer. You might want to check into a job in customer service. Or, if you are into movies, it never hurts to get a job at a video store.