You can apply for an SBA loan through your local banks. They will require several items, the first being a completed, formal business plan. They will also require that you have 20 - 30% of the start up cash yourself. Then it's a simple matter of taking your business plan to a commercial loan officer. They will decide if it is worth forwarding to the SBA representative. You will complete paperwork for the loan application and wait for SBA approval or denial.

They will also expect to see applicable experience in the industry you are going into. They want to be sure that you have the experience and skills to successfully run your company.

The business plan is key. That is what will get your foot in the door. (See below for help.)
http://smallbusinessstartup.biz/plan/