Final answer:
The second most important and most effective step in neonatal resuscitation is ventilating the lungs.
Step-by-step explanation:
The second most important and most effective step in neonatal resuscitation is ventilating the lungs. When a newborn baby is not breathing or is having difficulty breathing, providing ventilation helps deliver oxygen to the lungs and remove carbon dioxide. This can be done using various methods such as bag-mask ventilation or intubation.