1. Print an on line visit visa form, that would give you adequate information.
2. Interview is the most important part of US visa, where you would have to satisfy the interviewer that you have a stable job in Qatar and you are only going to visit the US monuments and tourist places like, statute of liberty, white house, Niagara fall, twin towers etc. after which you would return to your job.
3. Your bank statement should have adequate balance to support your visit.