Generally, a foreign national will require an employer who is willing to sponsor a particular visa process in order to move forward, usually an H-1B, L-1A & L-1B, TN, Labor Certification or PERM and O-1. This requires a job offer from the sponsoring company or organization, and the employer will remain actively involved throughout the visa process.
Choosing the most appropriate visa process depends largely on the unique circumstances in each case. Additionally, different visa processes can be lengthy and costly. It is important for both the employer and the prospective employee to be familiar with all of the available visa options before deciding on the most appropriate course of action to increase their chances of success.