If you are doing this as a self employed person and not employed by anyone (meaning not getting wages) than this will be considered as your self employed income to be reported on Sch C.
You also need to be aware that you will owe self-employment taxes
on any profit in addition to income taxes. These are calculated on Schedule SE.
In arriving at the net income subject to self employment tax you can deduct any costs associated with earning the income - toys, food, cleaning supplies, etc. that are "reasonable in amount and necessary in carrying on the business."
Self-employed individuals, sole-proprietors, independent contractors and persons who have net earnings of $400 or more are required to pay self-employment tax by filing Schedule SE (PDF), attached to their Form 1040, U.S. Individual Income Tax Return.
So you will file tax return if your net earnings from self employment is $400 or more.
Let me know if you have any question.
Please note: This advice is provided with the understanding that all the relevant facts have been provided by you. Any change in facts might affect the advice given and hence may not be relied on in such cases.