The new version will have a full manual.
> Should my 30 dwarves with little to no armor and wooden shields have been able to take down a
> Hill Titan whom has venomous bites with 1 casualty and 4 wounded dwarves?
Sounds like a pretty even match up to me. Run it in the arena 10 times and report the results? Masterwork mod has a pretty small effect on this scenario, for example if some of your dwarves were from castes which improve their strength or agility.
> Turrets - Who, what, how, why?
Who: Dwarves
What: Turrets
How: Buy them from the caravan and station them as if they were animals in pastures behind fortifications. Fire, web and other turrets do area damage and are awesome, but you might want to start with Bullet and Slade turrets, these fire rock like projectiles with no friendly-fire danger. The turrets that you can craft are more complicated and can be a little bit frustrating to deploy, so my advice is for new players to stick to the purchased ones.
Why: To shoot stuff at your enemies. Gives you some more options, because vanilla siege engines are even more complicated to deploy effectively.
> Psychiatrist?
Is just another noble with the responibility to Pacify & Console unhappy dwarves, that kind of thing.
> Does this mean that if my dwarves have a problem with something they can get happy pills?
> If a dwarf is throwing a tantrum, do the guards now pin him down and force him to take Ritalin/Rita-out?
No, he just meets unhappy dwarves in his office. (edit. ... well, actually there may be music and drinks that can soothe angry dwarves, come to think of it, but it has nothing to do with the psychiatrist)