Lets say I'm writing a passage which concerns some "things"..

In english I can write "these things are:", and after the ":" (which I don't know how you call it in english), I can continue by writing what these things are.

Is it possible to do something similar in klingon ? Can someone write {Dochmeyvam bIH:} or {bIH Dochmeyvam'e':} ? And then continue by describing whatever it is he wants to describe ?

And if the answer is yes, then what is preferable/more correct ? {Dochmeyvam bIH:} or {bIH Dochmeyvam'e':} ?

It's called a colon, and as part of a sentence it is typically used either as you are using it here (enumerating a list) are as an explanation or definition of what comes before the colon.

The Bird of Prey poster uses colons in some of the Klingon text.

In normal speaking, I wouldn't rely on this. Just put your list in the normal place: Doch wa', Doch cha', Doch wej je bIH Dochmeyvam'e'. Don't look to punctuation to be able to speak in new ways; use punctuation to make clear the text you write.

-- 
SuStel
http://trimboli.name