If you installed the Office 365 Home Premium Preview, you can create a new document using Office on Demand by going to
www.officepreview.microsoft.com, signing in with your Microsoft account and then, on the MY OFFICE tab, clicking
Create New for the application you want to use. You will be able to start working on your new document within seconds—even before the streaming of all features is complete. You can also access existing documents using Office on Demand either from
www.officepreview.microsoft.com or from SkyDrive. Just sign in with your Microsoft account and open the document you want to work in. The document will initially open in its Web App, but you can open it in the full application from the Web App.
If you installed the Preview version of Office 365 Small Business Premium or Office 365 Enterprise, you can use Office on Demand by logging into your account at
www.office365.com on a PC that doesn’t have Office installed. Then, go to SharePoint and open the file you want to work on, selecting the option to edit the document in its application.