how to write letter request?

I understand where your coming from. I believe you should include these in your letter: 1. The reason why your asking for Financial Assistance; 2. The condition of your father (attach the medical abstract I believe that is necessary); 3. The estimated cost of the procedure (chemotherapy, surgery, or alternative medicine); 4. If your father has been hospitalized and you want reimbursement, include the billing statement of the hospital; 5. Attach all the necessary documents; 6. Make it brief yet complete; and 7. Also include why you need the assistance, such low salary and the number of people depending on you for sustenance. Make the letter such that the reader would know the situation and and understand the instant they read it that you deserve the FA. It would also help to have the endorsement of government official (Congressmen, senators, mayors, et al.)