To make a folder Web Accessible, you need to change the rights for Public from none to Read.
Click on the Share button next to the folder you want to share.
Set the permissions for Public to Read and click Apply
You will be asked to confirm the changes to the permissions. Click OK to change the permissions.
The URL for this folder will be http://netfiles.umn.edu/users/{Internet ID}/{Folder} where {Internet ID} is your Internet ID and {Folder} is the name of the folder you are sharing.