You can right click the files and choose to not share them. If it's the whole folder, then unshare the folder.
When you installed LW, did you allow it to search your hdd for files to share? That may be why it's sharing files from your documents folder. I never allow it to search for files on it's own.
Files deleted from the LW library don't go to the recycle bin, unless your using the beta version.
Deleting Files From Limewire Library-don"t - File recovery advice!