To submit to an agent, send in your child's photo/s with name, age, height, weight hair and eye color and contact number on the back of each photo (one close-up and one 3/4 body shot if possible), a resume and a brief cover letter stating that you are looking for representation for your child in whatever fields you and your child are interested in whether it's Theatrical (Film and TV) (in NY Theatrical includes Film/TV & Stage), Commercial, Print, Stage, Voice-over, etc.
A legitimate agent does not advertise in the paper or approach you in the mall, solicit by mail or on the phone. Those are the "scam" artists to avoid. Legit agents only accept 10% of jobs booked, with nothing in advance. They do not demand you use "their" photographers or take "their" classes or use "their" vendors. Legit agents will recommend places for you to choose from. To be sure an agent is licensed go to www.dir.ca.gov/databases/dlselr/talag.html