This article is from the Sliders FAQ, by Ed Hall firstname.lastname@example.org with numerous contributions by others.
Books and stories having to do with parallel universes.
"Time Patrol" (and sequels) by Poul Anderson
"Ox" by Piers Anthony
"Virtual Mode" (and sequels) by Piers Anthony
"The End of Eternity" by Isaac Asimov
"Eon" (and sequels) by Greg Bear
"The Maze in the Mirror" by Jack L. Chalker
"Fireball" (and sequels) by John Christopher
"Lest Darkness Fall" by L. Sprague de Camp
"The Wheels of If" by L. Sprague de Camp
"The Infinite Worlds of Maybe" by Lester Del Rey
"The Man in the High Castle" by Philip K. Dick (won the 1962 Hugo award)
"The World Next Door" by Brad Ferguson
"The Woodrow Wilson Dime" by Jack Finney
"The Difference Engine" by William Gibson and Bruce Sterling
"Replay" by Ken Grimwood
"Job: A Comedy of Justice" by Robert Heinlein
"The Number of the Beast" by Robert Heinlein
"The Proteus Operation" by James P. Hogan
"Thrice Upon a Time" by James P. Hogan
"Worlds of the Imperium" (and sequels) by Keith Laumer
"Einstein's Dreams" by Alan Lightman
"The Dark Tower" (and sequels) by Stephen King
"Alternities" by Michael P. Kube-McDowall
"At the Narrow Passage" (and sequels) by Richard C. Meredith
"Elric of Melnibone" (and sequels) by Michael Moorcock
"All the Myriad Ways" (short story) by Larry Niven
"Crossroads of Time" by Andre Norton
"Lord Kalvan of Otherwhen" by H. Beam Piper
"Para-Time" by H. Beam Piper
"The Coming of the Quantum Cats" by Fred Pohl
"The Anubis Gates" by Tim Powers
"Trips" (short story) by Robert Silverburg
"The Probability Broach" (and sequels) by L. Neil Smith
"The Guns of the South" by Harry Turtledove
"Crosstime Traffic" (short stories) by Lawrence Watt-Evans
"The Universe Next Door" (and sequels) by Robert Anton Wilson
"Stranger Suns" by George Zebrowski
"Nine Princes in Amber" (and sequels) by Roger Zelazny
"Hyperspace," by Michio Kaku
Required reading for all would-be Sliders. Quinn was reading this book
in the pilot before his first slide.
"The Fourth Dimension," by Rudy von Rucker
Covers the basic concepts of the Einstein-Rosen bridge, with cartoons.
"Lorentzian Wormholes," by Matt Visser
Discusses various theoretical types of wormholes including the ever
popular Einstein-Rosen Bridge. Also includes a section on time travel
by way of wormhole.
"Parallel Universes: The Search for Other Worlds," by Fred Alan Wolf
Explains the quantum physics theories behind the concept of parallel
universes, then moves on to some speculation about parallel universes.
"'Relative State' Formulation of Quantum Mechanics," by H. Everett III,
Reviews of Modern Physics 29, pg 454-462 (1957) [also see Hugh Everett
III's Ph.D. thesis submitted to Princeton University on March 1, 1957]
Everett's theory introduced the original concept of parallel universes
as a real scientific theory, entirely consistent with quantum
I'm sure these lists (especially the first one) will grow over time.
Contributions are always welcome.