Welcome to the Children and Youth Service Directory page. Below is a list of the services that Yolo County Health and Human Services Agency provides for children (ages 0-18) and youth (ages 16-21). if you click on the service you are interested in, you will be taken to a service overview, which will provide contact information and a brief description of the program. If you'd like to learn more about that program, click on the link that is provided within the brief description.