When I started reading Terry Pratchett, I sort of jumped right in.  I did not realize how intricate a pattern he has weaved within his separate-but-related plotlines.  I thought it might be helpful for beginning readers to have a brief outline of how the various series go. 

Mind you, this is not an exhaustive listing of the interactions, merely a general overview of where to begin your reading in Discworld.



The Wizards Storyline:

The Color of Magic
The Light Fantastic
Sourcery
(Faust) Eric
Interesting Times
The Last Continent
The Last Hero



The Witches Storyline:

Equal Rites
Wyrd Sisters
Witches Abroad
Lords and Ladies
Maskerade
Carpe Jugulum
The Wee Free Men
Hat Full of Sky



The Death Storyline:

Mort
Reaper Man
Soul Music
Hog Father
Thief of Time



The Watch Storyline

Guards!  Guards!
Men at Arms
Feet of Clay
Jingo
The Fifth Element
Night Watch


Not-Quite-A-Storyline Storylines

Pyramids
Small Gods (which precedes Thief of Time and Carpe Jugulum)

Moving Pictures
The Truth (which precedes Night Watch, but comes after Fifth Elephant)
Going Postal

The Amazing Maurice and His Educated Rodents (precedes Hat Full of Sky)



As you can see, you could just pick up any Pratchett book and start reading it, but it would get quite confusing if you wanted to continue doing that through multiple storylines.  Good starting points are any first book of a main storyline.  From there, you can map out how the plotlines interweave (I even think someone at alt.fan.pratchett made a color-coded graphic to show the way each book interacts with the others), but this preliminary guide should suffice for beginning readers.


N.B. Since there are no reviews for many of the Discworld books, I am trying to write a couple each week.  I'll link to them in this guide as I get to each one.