I have never played against a daemon army before. Tell me, whats their general strategy, I play kroot (swarm army) whats the best approach to go if I wanna beat them?

The mission were playing, if it helps, is annihilation.. yeah idk if that was a good choice.
But basically, how do you go about beating them? And are there any secret ridiculous rules or specials that I should watch out for?

I've never seen any one play chaos daemons (dee-mons? or day-mons?)

Well if you have a choice of turns give them the first turn because they deepstrike half their army in on the first turn. if you went first you'd have nothing to shoot at.
They are more of a hey surprise i'm gonna rip you apart or shoot you to death army depending on what type they are. I can't say much else. try to get them before they get you

make there troops as slow as possible like the bloodletters.

yh, i agree with u sunbreath, the type of army they play realy decides on hw u should play

i dnt realy know, maybe try and lanuch ur own assault and have lots of troops??

ok, many troops, let them go first, stay a little bit away.

I play with a guy that used daemons, and you want to keep out of close combat with them, they don't have many range weaphon, but the soul grinder is the one that you need to worry about. I have loss many of tanks to a soul grinder, with his tongue and spit attacks.