A haiku is a seventeen syllable poem in three lines. First line has five syllables, second line has seven, third line has five. Traditionally, a haiku tries to evoke meaning more than it tries to mean anything in itself... or, to put it another way, it tries to capture a moment in time, both subjectively and objectively. But you don't really have to remember that last part. I've already forgotten it.
If you already knew all that, I apologize for speaking down to you.
So the game goes like this. First player comes up with a five syllable line, second player comes up with a seven syllable line, third player comes up with a five syllable line, and then the haiku is complete. Fourth player starts a new haiku with a five syllable line, fifth player follows with a seven syllable line, and so on....
If this seems complicated to you, read it again. All the information is there.
So, I'm the first player. And I start with a five syllable line. Which is this:
Dark snow ringing falls
(Your lines don't necessarily have to make sense, but it would be nice if they at least made sense to you)