Never ever trust people at work, specially the person who benefits from you.He will be only looking for his advantage.People exploit you for their own benefit.
There is no place for friendship in office.Its professional life so let it be like that.
Dont get emotional at all.Just think how you will get benfitted from some one/thing because everyone else thinks that way.
Be careful when you send out mails because they may be used against you also.
Dont ever confirm in mails, it might be risky at times, but always get confirmations through mail only.
Being frank always helps you.Dont ever try to hide something and put a false reason which you cant defend yourself.
Before convincing some one first learn to convince yourself.
There will be many who talk softly with you as if you are their closest friend when they need some work to be done by you but when that is done they go back to their normal mode of back stabbing.They think they are ultra-cool managers.
A very important thing is get yourself clear with policies of company.This will help you always, because ignorance is suicidal in this case.