On Windows servers file/folder read and write permissions are set via the control panel file manager.
From the main page of your plan click on "file manager" and navigate to the object you want to alter the permissions of.
We suggest only changing permissions of objects within your wwwroot folder as other folders have specific permissions preconfigured which should not be changed.
Once you have found the object to change, click the padlock icon next to it and a dialogue box will show you the user permissions you can set for this object. Typically this will be a "network service" user and "yourdomain.com" user, you may also have other domain users from other websites within your plan that you can also set.
For people to view the object via the web then it must have domain user read permissions at least. To allow your web application to write to the object then tick the write permission box and click okay. On folders you can also tick the "Replace permissions on all child objects" box to have the permissions propagate to all child files and folders.