[BumFace]

Some tips from my experience as a teenager lookin for a job:

Get up really early and get yourself down to the market whilst they are unloading and ask around - someone has usually not turned up (due to it being 6am on a Sat morning!). Don't be shy, ask everyone and if they say "no" then ask if they know anyone who does need help. I got a great job in the indoor market when I was 14 which went from 2 hours unloading to working on the stall to getting a Summer job at the wholesalers we went to.
When I left school I wrote a number of letters to companies I was interested in working for, made myself look smart and went around and hand delivered them (again to show you are willing to get off your backside, anybody can write an email!). This led to a job in I.T. and I haven't looked back since.
Show willing and show some initiative and when given a chance make sure you are reliable and make the most of it.

One other thing - consider yourself lucky, I'd do anything to be 16/17 again!