Courtesy of the DRAMA Notebook site, 400+ FREE plays are readily available to use immediately. The Free Stuff section of DRAMA Notebook also includes Drama Games for Kids,
Plays: The Drama Magazine for Young People. Available both in print and online from the Education Library.
Current issues of the print edition are available on Floor 1, with previous years on Floor 2. All may be borrowed for 2 weeks.
FREE scripts for reader's theater from Reader's Theater Editions, a site managed by Aaron Shepard. Aaron's Indexes are a helpful guide to finding the type and grade level scripts you need.
Story Vines and Readers' Theatre by 
Readers' Theater, Grade 4 by 