If you have a look at your heat gauge it will list everything good / bad about the mood of the prison. Armed guards in service cause negative vibes.
See attached - screens taken seconds apart, but in one I added two armed guards - danger level begins to rise!

You'd be better off making choke zones around the prison and placing metal detectors - simply use the dogs on the most used pathways / yards / patrols through any rooms on the intelligence view where weapons and contraband can be gotten (this includes the offices - those shrinks are dangerous!).

As to visitation centre - I only ever have a single guard deployed there to open / close the doors and gates and maybe another patrolling nearby in case things kick off (only really heppens with gangs).

Thing is no one strategy works universally - as your prison changes, so must your plans, and you also have to change things you did long ago. - Get gangs arriving in the clink? - get rid of any normal doors and have "locked open" jail doors instead - this keeps heat down but provides security for WHEN they try to break out.

Oh, and unless you want a really difficult game - NEVER have the fog of war turned on.

EDUCATION

When I look online it tells me that 'ALL ROOMS BOOKED" might be a bug, but somehow I'm doubting it.

I have a classroom and desks and schedules three hours a day for "work" but I still get this. Meanwhile my classroom sits empty.

I finally figured out how to have carpentry classes but that's in the Workshop.

Have you checked the schedule manually? - Your work periods may not be long enough for the lessons.
When I get enough to make it profitable - I'll often use the holding cell for max sec cons until I have more than a dozen or so - I'll also put them on a different regieme.

Okay, I think I got it, but this is fucking confusing. XD

Most classes need three hours, but the main education one needs three STRAIT hours. The others can be three separate one hours classes per day. :P I had to redo my entire schedule (my biggest problem being meals) but looking at it my prisoners are virtually never in their cells now so that should make them happy.

Well the woodworking and shop stuff are done in the workshop so that right now makes two classrooms. Besides I want to get my manufacturing going on. I'm paying these guys and they aren't doing anything! :P

Low sec and med sec cons seem to be best for the workshop - although now all three of my max sec guys are chucking out superior beds like farts in a jaccuzzi, they all started as min sec.

If they have a yellow circle, select the prisioner, go to the experience tab, and you should see a recruit informant to the right of the mugshot. Carefull not to blow their cover after being recruited tough

Thank you! :D

BTW, to anyone interested, I had my first major tunneling incident and read in a Wiki that a great way to work against that is monitor prisoners who are always tired. Right before the big breakout I noticed there were several guys moping around with "tired" written over them, even after a full nights sleep. It never occurred to me this might mean something but now I know, they were up all night tunneling.