I tried to be a real dwarf and take control of the water supply, it didn't work out. I didn't know water could travel up a well..
the flooded area you see in this image was my great hall.
shortly after i was ambushed and the whole ambush got caught in all my cage traps. I made a large pit and told the dwarfs to drop the goblins down the pit. They then made the choice to take the Goblins OUT of the cages to put them in the pit, my fortress was then quickly dismantled.
Things on my list not to do so far is:
1. Expect years trained veterans to be any good.
2. Expect my crossbowmen to understand how to shoot out of a tower.
3. Don't dump refuse and corpses near the local water supply.
4. Get soap before lowering the gate to the outside world.
5. Don't dig to far down, those forgotten beats have already destroyed me enough times.
(stub nosed crocodile thats explodes with a deadly dust every few seconds that on death gives all the surrounding dwarfs infection)
6. Don't think that the fortress is going well, thats when something bad happens.
7. Don't try to rush a single goblin with all your inexperienced dwarfs, somehow the goblin will pull through and slaughter everyone.
8. When your safe in your fortress with the gate up and Goblins on the other side want a fight your experienced warriors, don't lower the gate to be a gentleman.
9. Don't trust on the intelligence of dwarfs.
(9'th of obsidian A trade caravan arrives, i tell the dwarfs we will sell the goblins to the elf caravan. Then they proceed to free the goblins and ask them nicely to come to the trade depot, the result was a few mutilated goblins and a hurt fisherman)
10. When you think you understand water YOU DONT! just be happy with the water supply and the farm irrigation you get.