The International Ibsen Bibliography
http://www.nb.no/baser/ibsen/english.html
This site features several thousand entries in a database devoted to references to Ibsen's works in all languages, including books and articles about Ibsen and his works.
Ibsen.net
This site is devoted to disseminating information on Ibsen's life in Skien. It mainly focuses on such things as the city's cultural festival, though it includes some interesting biographical information on the playwright. It also contains a section on current productions of the plays.
Ibsen Center
http://www.hf.uio.no/ibsensenteret
The website for the Ibsen Center at the University of Oslo. The institution was founded to "strengthen and coordinate national and international research on Ibsen." The site provides biographical information, a collection of his writings, and an extensive archive of studies of Ibsen and his works.
Henrik Ibsen
http://www.imagi-nation.com/moonstruck/clsc5.htm
Imagi-nation's Ibsen website provides a biography of Ibsen as well as links for purchasing all of the works currently in print. Also check out the page devoted to movies based on Ibsen's work, plus the series of excellent articles available online.
E-text of the Play
http://www.gutenberg.org/etext/2542
The Project Gutenberg e-text of the play, translator unknown. The translation seems fairly old-fashioned.
ISU Play Concordances: A Doll's House
http://www.public.iastate.edu/~spires/Concord/doll.html
A searchable concordance of Michael Meyer's translation. It is an excellent resource that uses the best available translation.
Ibsen's "A Doll's House" Set Design
http://josh.st/blog/2004/10/29/ibsens-a-dolls-house-set-design
A useful visual aid for imagining the room in which the play takes place.