I need a job?

Now im almost 16 and i want to know where and how to get a job. Where should i apply and what to do when applying,What to put in my application,ect. I really HAVE to work soon because my familys financial situation just took a turn for the worse and if i were to work,the extra income would keep us afloat. What should i do to get working as quickly as possible? I do have a back-up plan (Working in the fields) But its such a painful job and i cant work there until i get my license
(Ill be getting my license in 3 months,I already have my permit,ect and a minivan which belonged to my grandfather before he died)
Basically,Where should i apply,What should i add into my application?
(Please dont tell me i shouldnt work,Nobody else in my family can work,Dad is gone,mother is collecting SSI because she is deaf,My brother is completely unmotivated,And he has a social disorder)