In the top right corner of the screen, click the Sign Up button.
Select Parent from the options.
You should have received a Parent Access Code from your child's school. Enter that Access Code in the text box.
Enter your name, email address, and password. Once you log in, you'll be able to browser your child's activities by selecting your child's name from the top right dropdown.
You also have the option to associate additional children using Schoology with this account. To associate additional children, click on the downfacing arrow on the top right of your Schoology account, select Add Child, and enter the Parent Access Code for your other child/children.