PRIZM (Pretty Reliable Invisiclues for Z-Machine) offers InvisiClues files you can download for Infocom's games.

The Infocom Document Project is also hosting copies of the PRIZM files, but also contains the maps that accompanied the InvisiClues books..

The Infocom Walkthrough Archives is a "page is dedicated to the people who have taken time to send me walkthroughs and to E-mail me with ideas and typos, formatting problems, and the like. This is also for those unsung heros who took the time and effort to beat those games that the rest of us deemed ubeatable, and were nice enought to document their efforts so that the rest of us could have the joy of beating the games."

The Hotel New Zork has an easter egg hidden amongst its rooms: InvisiClues for Zork: The Unknown Underground. ("Undiscovered Underground" sounds a little bit like a Star Trek movie.)
Note: if your web browser doesn't have Java support, click here to enter the hotel lobby directly.

The back half of the room contains Aimfiz scrolls that will transport you to websites containing hints, maps, walkthroughs, et cetera, for a variety of game types.

Interactive Fiction Archive:
main FTP site - WWW version - U.S. FTP mirror - U.S. WWW mirror

IF-A-Minute condenses IF games down to "sound bite" size. Some have some pretty bad puns in them (but then again, there is no such thing as a "good pun").

Adventure Collective "is an international collaboration between computer game enthusiasts who share a common interest in playing adventure games. It is the most comprehensive internet game site that focuses exclusively on computer adventure game series or collectives." Currently, the site offers interviews with Dave Lebling and Steve Meretzky, and a review of Planetfall.

Balmoral Software offers hints for Return to Zork, Zork: Nemesis, Zork: Grand Inquisitor and Zork: The Undiscovered Underground, as well as many other adventures like Riven and The Longest Journey.

The Classic Adventures Solution Archive is a site that wants "to be the best resource for solutions for classic (8-bit) adventure games and interactive fiction - this means Spectrum, Commodore 64 and Apple II in particular, but also BBC, TRS-80, Amstrad, Dragon etc."

The Spoiler Centre, where you can search for games that are organized by company in each genre.

Mr. Bill's Adventureland (formerly Mr. Bill's Adventure Game Website) "reviews and previews of adventure and puzzle computer games, walkthroughs, hints, help, message board, links, where to purchase, for how much: includes the old classics."