Physically browse most of the monologues and dialogues in Langson Library by browsing in call numbers that start with PN2080.
Other tips:
Browse monologue anthology titles by doing a SUBJECT search in the Library Search for 'Monologues.' A keyword search for 'scenes and monologues' also retrieves some books containing scenes.
There is no specific subject heading for scene books, but scenes are frequently included in monologue anthologies.
Some plays are published individually and some are published in anthologies (multiple plays printed together in one book). Plays published individually are very easy to find. Search in Library Search using a title, author, or keyword search.
Locating plays in anthologies can sometimes take a few extra steps because the individual plays are not always listed in the catalog, but just the name of the book (e.g., Twenty Best Plays of 1990).
Try searching for the play title as a KEYWORD in combination with the playwright's last name (e.g., Cat on a hot tin roof AND Williams)
Try searching for the playwright's name and one of the following words: DRAMA, PLAYS, or WORKS (e.g., Tony Kushner and plays)