To serve as Pilot In Command of a large (over 12,500 pounds) or turbojet aircraft, you must have a type rating in that aircraft. Normally, training for the type rating is conducted in a formal training environment, using simulators and advanced training facilities.
The Type Rating Test (check ride) is normally conducted adhering to the Practical Test Standards, although at some airlines the rating process is conducted using the Advanced Qualification Program (AQP) with proficiency determined at various milestones during training.
The Practical Test Standards are spelled out in FAA document FAA-S-8081-5F. This podcast discusses tips for success in your training and advice for a successful Type Rating Test.