There is no "Uploading " in the sense that you upload a file to a server (like with Megaupload or Rapidshare).
By including folders or files you're willing to share via the share option in LW, other users will be able to see your files in their searches and can download them from you (as the host of the file).
Go LW>Tools>Options>Sharing>Add...
There you can add those files and folders you want to share.
