To add a member to your organization as a player you can select "New --> Member" and fill out the information. This will send an invite to the parent of that member. Once the parent have accepted the invitation the individual will become part of your organization with the role of parent.
If there are additional parents of the player you would like to invite then you will need to either use the "Invite" option or let the parent invite others in with the "Invite Friends and Family" option..
You must have a product to associate the player with. This is later used to filter players for creating teams, or if you want to send email to all members that are associated with a product.
The "graduation year" is not required. The number will assign a default number to the player that will be used whenever they are added to a team with the matching sport. If you do not currently have a number assignment for the player then you can just assign a default number and edit it later when there is a number assignment.