"BOOK" FILES:

Our protagonist comes across all of these over the course of her adventure. If you're reading the comic for the first time, they may spoil certain plot points, but I've included which pages they appear under!

The "Cake" Story (Appeared on page 349)
Understanding Concept Cores (Appeared on page 458)
The Very Hungry Original Flesh (From page 571)
Jay's Journal (Page 599)
The Grey Zone and You (Page 675)
Doctor Man's Journal (Page 697)
Doctor Man's Photos (Page 698)
Error Log (Page 704)
What are Worms? (Page 916)

THE ZONEHOPPER'S GUIDE (ongoing series):

A series of loosely connected stories set in the same universe. These contain no spoilers or direct references to events in Awful Hospital, but flesh out and explain how the setting basically works.

Entry A: It's Alright to Panic
Entry B: My Story
Entry C: The Bossman
Entry D: Into the Range
Entry E: Apparently it's Foaming Season
Entry Fifgreen: About Concepts
Entry Ungeorge: The Crevices
Zonal Field Guide I

CHARACTER CHATS:

These can be read at any point, but some may prefer to read them only after these characters have appeared within the comic.

Mizer's Employee Evaluation
Phage and Tori's lunch meeting
Jay Meets Dr. Man
Parliament Meeting

Phage's Character Files:

Read character files at your discretion after encountering any of the relevant characters!

Nobody Nose
Circula Tori
Phleboto Mizer
Stomach Guy
Molly Curdle
Spleonard Spleenus
BBQ Girll
Eyeda Sorrit
Harmburger
Angus Cobb
Kidney Stone
Oozing Skull
E.M. Balmer
Bloodstain
Open Wound
Willis
Millie Curdle
Gynnie

Balmer's Character Files:

Delia or something
The doctor one
The Swamp Witch
The Other Witch
Worms... WORMS!
That Green Thing
Dr. Phage
Me

Circula Tori's Character Files:

Phagey
Chip, the coffee guy
The Snippers
...Cathy???
Crash the Computer
..."Gardenia?"
Dinea

Character Journals:

Circula Tori
Harmburger
BBQ Girll
Spleonard
E.M. Balmer
Maya Celia

BESTIARY SERIES 1: THE PPP ASSOCIATION

Kidney Stone Child
Ramblin' Evil Colorectal Polyp
Contaminated Biobag
Slob

Miscellaneous Files:

EBSHA file #Q0092L: The Drive-In Menu
KNOW A MEEPTZ
Blights of the Perception Core

Other Canon Media:

ABYSSAL (on Newgrounds) - A 2009 flash horror short.

HARMBURGER (short story) - The first thing ever knowingly written in what would become Awful Hospital's universe, part of a trilogy known only as Noisy Tenant.

DR. PHAGE (short story) - Phage's first creepypasta appearance and the second Noisy Tenant story.

DR. DEMENTIST (short story) - The third Noisy Tenant horror tale.

DR. FLEAGOOD DOES IT AGAIN (short story) - A third, "lost" noisy tenant story I finally completed in October 2015.

NAUSEA QUEST - 2012 twine adventure starring the L.B.K.E.N.M. Officially tied Abyssal and Noisy Tenant into one canon.

BORFLADGE - an alternate-reality Bogleech.com full of cryptic content.

The Burgrr entries - originally hosted on the official Harmburger website which has now been decapitated and eaten by some sort of goblin. You can now find the story on creepypasta wiki!

Quasi-canon media:

POKEWEEN - a perfectly normal Pokemon review series that in no way ties in with Borfladge.

DON'T GET SPOOKED - an illustrated comedy-horror text adventure with over 60 unique monster encounters! Walkthrough here. Not completely canon with Awful Hospital...or is it?