This document discusses how to insert nodes into a singly linked list at different positions: 1. To insert at the beginning, create a new node and link it to the head node, making the new node the new head. 2. To insert at the end, create a new node pointing to NULL and link the last existing node to the new node. 3. To insert in the middle, create a new node, link the node before it to the new node, and link the new node to the node after it.