Opera by Vincenzo Bellini
Libretto by Felice Romani
A plot synopsis of Norma can be found at the site of the Metropolitan Opera.
Opera Pages
Norma Libretto
at Barnes & Noble

Norma in Full Score (paperback),
46% off Bestsellers at BAMM.COM
Both of Maria Callas's studio recordings of Norma were conducted by Tullio Serafin.  The earlier of the two had Ebe Stignani as Adalgisa and Mario Filippeschi as Pollione; the latter had Christa Ludwig and Franco Corelli.  Over all, I prefer the later recording, but Callas's voice is fresher in the earlier.
Opera d'Oro has released, without a libretto, a recording of a "live" performance of Norma with Maria Callas, Ege Stignani, and Mario Del Monaco, conducted by Tullio Serafin.  Available from
Norma: in Full Score: (Sheet Music)
Barnes & Noble

Bellini - NORMA (MCD051306) with Joan Sutherland, Marilyn Horne,
Frano Tagliavini, Joseph Rouleau, From London, 1967, conducted by
Richard Bonynge.  Myto.

Bellini - NORMA (Naxos 8110325-27) with Maria Callas, Mario Filippeschi, Ebe Stignani, Nicola Rossi-Lemeni, Chorus and Orchestra of Teatro alla Scala conducted by Tullio Serafin. This 1954 recording has been released in a new transfer made from the best portions of two 1950s-
era British LP pressings which provide the most open and un-gimicked sound of several editions previously available.

Norma (G. Schirmer's Collection of Opera Librettos) (Paperback)