Selecting the "Create a folder" link will take you to the create folder form:
If you have a number of files that you want to upload you can make a .zip file of them on your machine and check on the " Unzip Archive" button.
If you are uploading a netcdf file (or another data type that can be opened, e.g., grib, radar, area file, etc) checking "Add Properties" will have RAMADDA crack open the file and harvest the time range, lat/lon bounding box, global attributes and variables and add them as a property of this Entry. See the section on properties for more information.
The "Data Type" is an optional and arbitrary data type that can be used to search for entries of this type.
The "Date Pattern" can be used to match on the file name to automatically figure out the date of this entry.
RAMADDA offers a number of different entry types that can also be created. Choosing "New Entry" menu link takes you to a rather daunting page that lists all of the available entry types.