The title of this activity: Investigative Challenge: Who is My Teacher?
1 Page PDF
Ready to use, no planning necessary.
Instead of simply telling students about yourself, challenge them to make observations and analysis about you and your room. Students record their observations and collaborate with others.
This is a great beginning of school activity for all subjects, especially science and language arts because it stresses subject-specific skills.
I often follow it up by allowing the class to ask me 20 questions as an "interview" to help them compose the bio section.