Before we discuss the practicality side of the RasPi, let's look at the precautions and tips when working with RasPi. You need to read this, as you are now going to work with the GPIOs of the RasPi. This section will give you generalized tips and warnings to keep in mind when working with the RasPi:
Avoid touching the electronic components on the RasPi, as even a small amount of sweat or a static charge from your body can spoil the board. The components on the board are so small that it can be affected by a very small amount of sweat in your hand, and by water too. Touch it from the corners, or always use a casing to cover it. There are a plenty of these available in e-stores.
Take care when putting the RasPi on the table. If there is a small metal part (cut pieces of wires) or the table itself is made of a metal, it can short the connections on the RasPi.
Never connect any device that provides voltage higher than 3.3V to the RasPi's GPIO pins. In Chapter 3, Measuring...