To amplify, when you show in the morning on the first day the the list on the wall and seating are in order of senority. Sometime in the morning, they will list all the spots. Example:10 NYC-7ER, 4 ATL-767, 11 NYC-MD88, etc. There will be exactly the number of spots availiable as there is people in the class. There are no left overs. After you come back from lunch, they will ask #1 what he wants, then #2 and so on. Usually the bottom of the list do not get a choice. Do your homework before you show up and think about what you want. You are allowed to ask questions like, will I be able to get back to ATL quicker in a MD-88 or 767?, and they will answer to the best of their ablilty. One guy said he was torn between MD-88 or 7ER. They asked him do you want to get back to Atlanta ASAP or see the world? He said see the world, so he picked NYC-7ER. There is no seat lock for new hires, so you can bid out at the next AE. If you switch airplanes, 2 year seat lock and more time in the school house in Atlanta. No lock for switching bases.
Good luck