I may have been working with my Arduino UNO board improperly, because now it fails to upload sketches (says some programmer is not responding) and when I press the cute little restart button, the green LED doesn't do its blink anymore. I am aware what that means, but what I really wonder is how should I properly care the board. I probably will have no other chances to buy more arduinos so this information follows to be of a great importance.

As an example I would give, is touching the arduino board with bare hands risky, how much shock-tolerant it is, what if I mistake some pins, are there pins that cannot be mistaken like is loading a PWM program onto TFT touch screen shield unhealthy and so forth.