I've set up my base and I've kidnapped the maid, the guard and the Chinese technician so I've got the three basic minion types besides the construction minion. So how do you obtain the more advanced minion-types? (I read in the manual that the bookshelf in the Archives area can be used as an interrogation device. Has anybody ever tried that and how did it work? )
I think you can only use the interrogation chair for learning secrets to create new minions. Any other device just kills the prisoner or releases them without you unlocking the new minion class, I believe. The primary use for other interrogation/torture devices besides the chair is tying up super agents and soldiers so that their time spent on your island doesn't involve mass destruction of your base and minions. When you aren't able to simply kill them outright. No one can escape while being tortured/interrogated (they can potentially escape before and afterwards though, if they're conscious). Many torture devices like the bookshelf (I think?) will lower one of the stats to zero as well, like how some traps work.
As Eddevilish said, it works the same way as with the basic minions. You gotta capture someone from the world map when the mission appears and once you've interrogated the prisoner and unlocked a new minion you'll need their specific training facility built to make more of them. If that first new minion dies before you can train more, you must do all this over again. Your basic yellow workers are the only ones who can interrogate a prisoner to unlock a new minion class---so you'll need some of these available as well.
I'm pretty sure the missions to kidnap the people that allow you to unlock advanced minions don't appear until your infamy is at a certain point. So you can't get advanced minions in the early game.
Hope this helps!