Before the high resolution computer graphic adventures of today, there were text adventures. At its prime, Infocom was the ruler of the text adventure gaming world. Today, these games remain classics. People still play them and many more are just discovering them.
The Infocom Page contains solutions for every single text adventure ever released by Infocom (plus solutions to a few of their graphic adventures).
The solutions give you a step-by-step guide through the games. Some of the solutions contain abbreviations like "I" for inventory and "N" for north. These abbreviations will work as written.
I suggest that these solutions be used only when hints are desperately needed. Better yet, once you have completed a game, you can use these walkthroughs to revisit the games, find out different ways to beat them, or improve your scores. Walkthroughs like these are ideal if you are interested in printing out transcripts of the games.
My solutions for Zork Zero and Leather Goddesses of Phobos 2 were originally published in The Book of Clues and Quest for Clues: The Manual of Swords, respectively. Both books were edited by Shay Addams.
When Activision released the graphic adventure Zork: The Grand Inquisitor in 1997, they included a short text adventure with it in homage to the original Zork games. The adventure was called Zork: The Undiscovered Underground. It is available as shareware for Windows in a .zip file and can be downloaded via the link (in the title) above. The zip file comes with a program called WinFrotz, which will enable you to run other Infocom games in Windows if you already own the DOS versions. Unfortunately, I cannot provide any tech support for this game.