How can i add Song info in large mp3 files

what media player do you use?
there are now plugins for the most to read cue files.
you can search cue files here: http://www.regeert.nl/cuesheet/index.php

the other way is to use lyrics. personally i don't use the synced lyrics, i stick with unsynced lyrics. there are also plugins for most media players to read them. the tag is %unsyncedlyrics%.

if the tracklist is writen in the form
[0:00:00] artist 1 - track 1
[3:30:00] artist 2 - track 2
[7:35:35] artist 3 - track 3
...
there are players which reconize this as "timestamped lyrics". i don't know much about that, found it out when i used a lyrics plugin for winamp where i was able to click on the timestamped line and the mix jumped to this position. it also highlighted the line wich was playin at the moment. worked perfect there. now i use the foobar2000 media player. the lyrics plugin is not as good. behaves somewhat inconsistant, but that's another story...

another oportunity would be to save tracklist in the comment tag, as this can also store mutliline comments per default in most players and you need no plugin to see them.

most of my dj mixes have only tracklist in the unsyncedlyrics tag as simple lists without time. that's enough for me.

p.s.: maybe interesting for you:
i made a special web source script which writes id tags including the tracklist when they are found at mixesdb.com:
/t/8404/1

i also made a export script which transforms tracklist which are stored in the %unsyncedlyrics% tag into cue files. it isn't fully working jet, but it may be a help:
/t/10946/1

and i made a second export script which gives you the head of a cuefile (the information wich links the cue file to the mp3 file) without tracklist. it is thought for use in combination with the cuesheet database given above:
/t/10090/1

p.p.s.:
ah i see, wmp12 is windows media player, right.
here are a few lyrics plugins i found with google:
http://www.chip.de/downloads/Lyrics-Plugin...r_33623026.html
http://download.chip.eu/de/Lyrics-Plugin-f...er_1063139.html
http://www.pcwelt.de/news/Download-Tipp-So...yer-187677.html