How Azkaban Works? WAS: Sirius' situation his own fault?

[M. Thitathan]

No: HPFGUIDX 142445

CH3ed: 
SSSusan and Alla were talking about the lack of visit from DD to Sirius while Sirius was imprisoned at Azkaban. 
 
I'm quite curious about how Azkaban works. For one, I wonder if visitation is allowed there except for some special circumstances like Barty Crouch, jr being near death so that his parents were allowed a deathbed visit (which turned covertly into a prison break)? Are there wizards working there beside the dementors (not the best job in the world, ay?)? I mean, beside guarding duties, there are the other duties like feed the prisoners. I think it'd be quite a punishment having to eat food being prepared and served by dementors... Talk about soul food! 
CH3ed