Here's the rules I'd use
Intimidate: the first roll. Only rolled once - it determines how good an impression the torturer makes on the mind of the victim, and how effective later techniques will be. A botched roll basically means "get a new torturer", unless that simply isn't an option.
The Intimidate roll is the period of time leading up to the actual torture. The torturer may leave the victim tied up for an hour or two (or all day), put on a big show of preparing the implements (and then break for lunch

), or even chat with the victim ("So, you and I know what's about to happen, but why let that stand in the way of my gloating?"). The roll sets the DC for the victim's Fort or Will save (whichever is better - tough people know they can tough it out; and tough-minded people are less likely to be impressed in general).
Some basic modifiers:
Improvised workspace: -2
Adequate torture chamber: +0
Masterwork torture chamber: +2
Less than an hour spent on intimidation: -2
1-3 hours: +0
All day: +2 (more than one day does not noticeably affect results)
Torturer is a size or more larger than the victim: +2
Torturer is smaller than the victim: -2
Torturer has something of value to the victim: +2
Torturer has 5 levels of bluff: +2 synergy bonus
Torturer is willing to let victim die: +2
Victim is willing to die: -2
(note: for PCs, just ask them "So... just so we're clear, if it comes down to the wire, would you rather break down and give up the piddling little info, or die?")
(note2: with
raise dead and similar, death may not be a bad option. That makes it really tough on torturers, but them's the breaks in a fantasy setting)
Results
If the victim fails their save by 10 or more: +4 on all subsequent checks!
If the victim fails their save: +2.
If the victim makes their save: +0
If the victim makes their save by 10 or more: -2.
Once you've established the first impression, it comes down to what results you want, and how you want to get them.
Getting Answers
Pain: Each hour, the torturer makes a Profession (Torturer) check. The victim makes a Fort save against the skill check. If the torturer succeeds, the victim will say something, anything, to make the pain stop. See "Talking", below.
Interrogation: Each hour, the torturer makes a Profession (Torturer) check. The victim makes a Will save against the skill check, OR chooses to remain silent. Remaining silent is fine, which is why torturers will want to occasionally shift to "Punishment" instead, below. If the victim fails the Will save, something slips out. See "Talking", below.
Talking
In general, a victim will try to lie
first, and only tell the truth if that doesn't work. A victim who consistently and constantly lies will probably proceed to "Punishment", below, if the torturer figures it out.
Each time the victim lies, this requires a Bluff vs Sense Motive check. If the victim is talking because he failed a save, the Bluff check is at -8. A victim who makes their save can choose to talk anyway, in which case there is no penalty to the Bluff check.
There is a cumulative -1 to the Bluff check for each hour of torture. A new torturer resets this value.
If there is a modifier due to how well the initial intimidation went, it is applied to the torturer's Sense Motive check.
Special: If the torturer's Sense Motive check beats the victim's Bluff check by 10 or more, the torturer figured out some of the truth despite the victim's best intentions.
Punishment
An hour of punishment requires a Profession (Torturer) check against DC 15. On a success, it does subdual damage equal to 1/4th the victim's hit points, and forces the victim to make a Will save against a DC equal to the torture check. Each hour of punishment gives a cumulative +1 to the save DC - this resets if the punishment does not
immediately resume when the victim wakes up, but otherwise continues accumulating.
If the victim fails the save, the torturer can specify a single,
highly specific action which the victim can NOT do. This is similar to a
suggestion. The usual technique is to state "do not lie to THIS question". The victim gets a new save each day to throw off the effects of the command.
Instead of a command, the torturer can elect to lower the victim's Fort and Will saves by 1, instead. This lasts until the victim has had a full day of rest for each -1 to Fort and Will saves the torturer has inflicted.
Slow Kill
The torturer makes a Profession (Torture) check. The better the check, the longer it takes.
under DC 10: oops, killed him.
DC 10: 1 minute per CON point.
DC 15: 10 minutes per CON point.
DC 20: 1 hour per CON point.
DC 25: 8 hours per CON point.
The above is probably only useful if you have some additional rule, like a feat that allows you to harvest 1 XP per 10 minutes from a dying torture victim.
There could probably be more detail, but that's generally sufficient for me

.
-seasong