On a Mac, you can add metadata to your tracks using the iTunes application.
Step 1) Open your file using iTunes. (In iTunes, select File -> Add to Library, then browse to your file.)
Step 2) Select the track, then select Edit -> Song Info.
Step 3) When the "Song Info" window pops up, click on the "Details" tab at the top of this window. You should now see editable fields, where you can input your file's information.
The fields of importance for Live365 are "Artist, Song Title, and Album." These fields correspond to the metadata fields in the Tracks section of Live365.
If you already imported the file into your Live365 library without all the metadata, you can also edit the metadata in the Live365 interface. Doing this only updates the cloud copy, so it is best to add or correct your metadata before uploading.