I don't live in Maryland, but it is pretty much the same across the country. Start by taking a couple of nice photos of you children. You'll want a headshot (picture of their upper torso and face) and one full body shot. Make them as natural as possible.
Write an introduction letter stating why you think your child should be a model. Agents are pretty particular about this. Most of them want it to be because the child wants to do this (not the mom).
Do a search in your area for talent agents (preferably Screen Actors Guild members). SAG agents must follow strict guidelines, thus you know they are legit. There are many not so legit agents just waiting to take your money, so be careful. Send your intro letter and pictures to the various agents asking them to consider representing your child. Then wait.
If an agent is interested, they will contact you to set up an appointment to meet you and your child. If you are signed, you will need to get some professional pictures. Don't get them until you are signed.
Never pay anything to have your child represented. Anyone who asks for money up front is not in your best interests. Agents make money when their talent book. Good agents (SAG) do not offer classes. In fact, they will lose their SAG standing if they do. It is a conflict of interest. Beware of those who tell you that your child needs to take lessons from them.
Good luck!
