DO -

Have Fun.
Take part in fun activitys.
Make Friends.
Stay safe.
Find a hobby in the hotel.
Be friendly.
Obey the Habbo way.

DON'T -

Give out your Bobba.
Trust anyone too much.
Give out any personal details, such as name, DoB and location.
Break any rules in the Habbo Way.
Do anything you know yourself is wrong.

Remember, Habbo was made for teenagers so they could have fun and make friends, but do be careful.

Keyloggers -
Keyloggers are nasty little files that get into your computer when you download something containing one.
Keyloggers store themselves into a file in your computer, and log the data of what you type, Passwords etc..
The best way to defend against them is to Always have your firewall up, and scan every file before you download it.
The best way to get rid of one is to Start up both a Anti-Virus and Anti-Spyware system about one a week and scan the whole computer.