goto (unless you have changed it manually) your LIMEWIRE SHARED FOLDER this can be found in OPTIONS (limewire options) and under the shared folder tab, you move all music files to there
-OR-
Click "Explore" to open your shared folder white on the library tab, then drag all files you wish to be shared here
As another option, you can just change which folder is shared, for example you can set "My Music" as your shared folder - and point videos, programs and other media files to their own folders - this is all done in the options > shared folders through the lime wire client
If you still need help, let me know! I'll add pictures next time :P
_S
_eith_