Exposition in Interactive Fiction - This document introduces the concept of exposition in interactive fiction, and offers three versions of the same brief interactive fiction text, so that you may experience interactive exposition for yourself. - http://jerz.setonhill.edu/if/gallery/exposition.html
Choosing a Text Adventure Language - Some handy tips about picking which language to use when writing a text adventure. - http://brasslantern.org/writers/howto/chooselang.html
Interactive Fiction Page - Information on playing and developing interactive fiction. - http://www.cs.cmu.edu/afs/cs.cmu.edu/user/wsr/Web/IF/
NPC Characterization - A guide on how to create believable NPCs. - http://emshort.home.mindspring.com/NPC3.htm
OnyxRing - Covers topics from interactive fiction design to Inform implementation. - http://www.onyxring.com/
Brass Lantern Interactive Fiction Theory - The theory of adventure game and interactive fiction design, from elements such as puzzles to game analysis. - http://brasslantern.org/writers/iftheory/