Dog walking, mow neighbors yards maybe even family that's gets lots of money, car washing, and babysitting! :) those are some FUN age appropriate jobs for 13-14 year olds. Maybe get your Bestie to do it with ya.
Warehouse jobs and jobs in retail are some of the most common jobs taken during summer. Restaurant jobs are also pretty common, so you might want to look into it. However, you will need to know your state's minimum working age, so that you don't get into problems. Check out www.gotajob.com/ for more on this.
Landscaping ...... do you know of anyone with a business started? Join them. Or go to your city council and ask (and get paid) to mow the lawn of empty houses! Sad to say there's plenty of them around!
I'd say working in an ice cream parlor or something similar would be good, because you get paid well, plus tip. You shouldn't want to work at a "serve yourself" place, because then you won't get tip. And, after a hard day's work, your boss might let you have some ice cream!! Hope this helped :)
Summer jobs really depend on your skill set - good jobs are data entry or retail in a large retailer on the high street but again it depends on what you enjoy ! You'll need a CV for the application - http://www.cv-genie.co.uk - write about your strengths and use the training course section.