Hi Hanadi
I also couldnt find a full free guide for The School for Scandal
I just got a summary from wikipedia
http://en.wikipedia.org/wiki/The_School_for_Scandal
and there is an MP3 file for the play in ARABIC ( it's literal translation so it's very helpful)
http://www.archive.org/details/P2-Dra-SchoolForScandal
buena suerte
good luck