By default your downloads will go into a folder, and this folder will be the folder you share. I am not absolutely sure where this is in Windows, but if you go to Limewire's options or preferences > saving you will see which your download folder is. Go to sharing and this will show your shared folder. Both these options can be changed, and you can share as many folders as you like, You just add them in options or preferences> sharing.
No other files on your computer will be shared.
If you alter your save folder to your music file then all your downloads will go there. You may then need to alter your shared folder(s) and also move or copy any files in your old download folder to your music folder.
I hope this helps ... Forgive my 1st question, but we do not feel well disposed to those who have no intention of sharing anything atall, and I wanted to ensure you were not one of them