Graham Nelson's (graham@gnelson.demon.co.uk) "The Craft of Adventure" (available from the IF-Archive) is a treatise on writing interactive fiction. This is currently in its 2nd edition and is also available as TeX source. HTML versions are available from "The TADS Page" and <http://www.inform-fiction.org> in PDF or HTML formats.
Gerry Kevin Wilson (whizzard@pobox.com) has thoughtfully published his views on designing and writing interactive fiction in "Whizzard's Guide to Text Adventure Authorship" (available from the IF-Archive). There are also two supplementary updates to this document.
Gil Williamson's (gil@cix.co.uk) book "Computer Adventures, The Secret Art" is now available as "literary freeware" (at <http://www.cix.co.uk/~gil/data/ca-tsa.htm>). This is primarily a "how to..." manual, and although many of the technical details are several years out of date, the book contains much of interest to the aspiring interactive fiction author.
The Oz Project, directed by Joseph Bates at the Carnegie-Mellon School of Computer Science, is developing technology for high quality interactive fiction. Focusing on the simulations behind the interface (which they call the deep structure of virtual reality) their goal is to provide users with the experience of living in a dramatically interesting simulated world populated with simulated people.
Michael St. Hippolyte's (mash@interport.net) paper, "A Plot Beyond A Line: New Ways to Be Nonlinear" <http://www.users.interport.net/~mash/nonlin.html>) looks at the problems of linearity in interactive fiction, and suggests some possible solutions.
David A. Graves's (dag@cup.hp.com) three papers, "Second Generation Adventure Games" (which focuses on the physical world model, parsing, text generation, and simple agent planning), "Bringing Characters to Life" (a summary of the progress in Artificial Personality during the 70's and 80's), and "Plot Automation" based on his presentation at the Computer Game Developer's Conference in 1991. All of his papers are available from the IF-Archive.
Authoring system manuals may be of interest, even if you do not use the particular system. Look for these in the IF-Archive, in the directory /if-archive/programming/<authoring system name>/manual/, where <authoring system name> is, for example, tads. Also, there is online documentation available for several authoring systems, as noted under "[Online Documentation]" in the authoring system records [What authoring systems are available?: 4.4] .
The TADS Manual contains useful advice on designing an interactive fiction game (chapter 6), some of which is TADS-specific, and some honest information on the limitations of the text adventure format (appendix B).
The Inform "Designer's Manual" details the step-by-step implementation of a small game as a tutorial throughout the manual (this is, of course, Inform-specific).
For further references try Stephen Granade's (sgranade@phy.duke.edu) "Interactive Fiction Bibliography" (1997), available from the IF-Archive in /if-archive/info/if-bibliography.txt .