Put your files into your Shared folder or else, create a folder & put the files in you wish to share. Then go to Tools>Options>Sharing & press add & direct it to where your folder for sharing is. The other way is to go to LW's Library window, menu File>Add folder to share. You might or might not need to press the Refresh button for LW to recount its shared files for this to take immediate effect.
In future please post your LW specific questions in the LW forum sections: Limewire Forum sections