Life can suck. There's disease, injury, high rent, final exams, warm beer, natural disasters, and death. There's lots of good stuff about life too, so much time is spent attempting to protect ourselves from the bad, that we completely ignore the good. Even when you're happy, it's difficult to free yourself from the memory and anticipation of stressful things. People end up living always for tomorrow, whether that means the anticipation of a promotion, retirement, a better job, or the Second Coming. Life is characterized by suffering, pain, and dissatisfaction.
The Second Noble Truth
The origin of suffering is the craving for pleasure, existence, and non-existence. You get it in your head that you want things, and your mind then becomes an instrument for chasing those things. The actual objects you desire are irrelevant; wanting things - anything - severely circumscribes a person's capacity to be joyful and serene. The body needs sustenance, but it's the self that craves pleasure, existence and non-existence, and it's the self that must be seen as insubstantial.
The Third Noble Truth
Some people say that all this talk of suffering makes Buddhism a pessimistic religion. And perhaps so it would be, if it weren't for the Third Noble Truth, the truth of the cessation of suffering; that there is a way to rid yourself of this suffering. Good news, eh?
The Fourth Noble Truth
You wanted a way out of the madness and stress? To rid yourself of suffering, you must follow the Eightfold Path. As you've probably guessed, it consists of eight parts. Get to know them, but don't expect to fully understand them right away. A fair amount gets lost in the translation when you're dealing with concepts. Read on to familiarize yourself with the path.