I think facebook is a great social networking site if used the right way, as stated above dont bother getting involved with the pointless games cause they are crap and will have you waste hours on it.
Also as mentioned above alot of people, companies and sneaky employers have turned it into a means of gathering info on you and use it to judge who you are.
Best way to use it is dont be a random adder, just add the people you actually know or have known be weary of adding anyone from work, or strangers who could be anyone using a fake profile to spy on you, employers, companies etc
Make your profile secure, keep it private that only your friends can view even the simplest info about you and even for the people you have added take the time to set what they can and cannot see.
It is however a great way for you to upload your pictures etc, so you can keep distant relatives, friends etc up to date.