Say the troublemaker's nick is "Jerk".

Simply type: /ignore Jerk

TADA! Anything "Jerk" types will be invisible to you!

Want to talk to a specific player, privately? Say the player's nick is "Friend"

Type: /msg Friend begin your message here.

Only "Friend" will see what you type.

You can check to see who votes for what by typing:

/stat

You can log chat and private messages by typing:

/log

Typing it again will turn logging off.