You can pick which assignment action should generate an email notification to your students or their parents from the Notifications tab within the Settings page.
Subjects are managed on the Settings page, under the subject tab.
Click on the 'new' button, which will display the Add a new subject popup. Enter the name of your subject, pick an icon and colour and click on save.
You can set up unlimited marking formats for use within your assignments. These can either be numerical or a select list. By default, you will have a numerical option of 0 - 100 and a select box of Grades A-F.