Folders are a great tool to have in Spike@School. To add a Folder just choose Folder from the Add a New: menu and click Add in the Construction Zone. You'll get this screen:
Folders are very simple, they just have a Name. Optionally, you can also give the folder a password. This is useful if you want to prevent the general public from looking at the contents of your folder on the front-end of your website. You could add a password, and then give it to the parents of the children in your class for example. Then they would be able to type it in on your site and view the stuff you've put in there. Folder passwords have no effect for users in the Construction Zone, you should use Permissions if you want to control access this way.
Once you've added a Folder you can click on its name in the Construction Zone to go into it. You'll get a screen like this if your folder is new:
From here you can add new items to the folder like normal.