Final answer:
The most important guideline to follow in beginning sound chaining activities is to have students add, change, delete, or move only ONE sound at a time.
Step-by-step explanation:
The most important guideline to follow when beginning sound chaining activities with students at the basic phonemic awareness level is to have students add, change, delete, or move only ONE sound at a time. This helps students focus on one specific skill at a time and prevents confusion. It also allows them to practice and master one aspect of phonemic awareness before moving on to more complex activities.