A: As long as you don't share your entire hard drive, you shouldn't encounter any significant security risks using Gnutella. However, make sure you are sharing only files you want to share, and to be completely safe, don't run executable programs that you obtain from the Gnutella network."
"Q: How do I share my files?
A: LimeWire will automatically share the files you've downloaded. You can also share files in several other ways. First, move files from other folders on your system to your LimeWire shared directory (c:\Program Files\LimeWire\Shared is the default location for the folder on Windows systems). In Windows, you can go to your Library Tab and click the 'Explore' button to open your library in Windows Explorer. Alternately, you can add a directory that you would like to share either by going to 'File>Add Folder to Share' to share while on the 'Library' tab or by adding a shared directory from the 'Tools>Options>Sharing' window. Click on 'Add' to Browse your files. "