A good beginner app note (PDF) from NXP on protecting ICs from ESD.
Integrated circuits are sensitive to electrostatic discharge (a sudden and short-time flow of currents) and electromagnetic fields (at which they can be source or victim of both of it). This application note shall be understood as an introductive basic description of what electrostatic discharge is, how sensitive devices can be protected against electrostatic discharges, what electromagnetic compatibility means and how electromagnetic sensitivity can be tested.