Each SBA lender requires different documentation and will ask a variety of questions during the application process. While each lender is different, for the most part it makes sense to have a business plan, know the amount and use of funds needed, have a good credit history, financial projections, collateral, and industry experience. The SBA has mentioned that even businesses with bad credit still have a possibility of being accepted.
On another note, things to have ready when filling out an application are the businesses past bank statements, identity verification, a business checking account, past tax returns, among others. As stated, every lender is different and will require different documentation