Documentation

The QEMU website has a Documentation page with pointers to the current actively maintained documentation including rendered versions of the user manual and selection of the developer documentation. More free form documentation can be found here on the wiki.

How do I...

For users

All user documentation pages

QEMU Main Documentation (HTML generated from QEMU sources, updated frequently)
Set up Networking
Setting up VirtFS (9P Sharing over Virtio) between the guest and host
Create a Snapshot
Ubuntu Development Ports - details on qemu-<arch> usage, chroot set up, system emulation and cross compilation
Compiling with qemu-user chroot - details on tuning binfmt_misc with magic patterns for making alien binaries run from the shell with silent invocation of QEMU
Use vhost-user with OVS/DPDK as backend
Set up storage for live migration
Replacements for removed features

Building QEMU from source:

on Linux hosts
on macOS hosts
on BSD hosts (includes info on setting up a BSD VM on a Linux host)
for Windows (natively or cross-built on Linux)

For users that target for a specific platform:

Running ARM guests on QEMU
Running POWER / sPAPR / pseries guests on QEMU
Running PowerPC Macintosh / Linux guests on QEMU
Running m68k Macintosh / Linux guests on QEMU
Running SPARC guests on QEMU
Running ALPHA guests on QEMU
Running OpenRISC guests on QEMU
Running RISC-V guests on QEMU
Debian on an emulated MIPS(EL) machine based upon some Debian Linux host
Windows XP on QEMU-x86 based upon some Linux host (brief but good hints on the guest set up)
Windows 2000 on QEMU-x86
FreeDos on QEMU-x86 based upon some Linux host (concentrates on host details)

For developers

Get started as a QEMU developer
Debug QEMU
There is a "developer's guide" in docs/devel, though it has significant gaps. You can see a rendered version of it on readthedocs
The wiki has a list of all wiki pages marked as developer documentation

Note that much of QEMU's internals are documented only in comments in the source code, or not at all.

Technical Documentation

The docs/ directory in the QEMU tree contains more user and developer documentation.
Hardware Manuals
Instruction Set Manuals (Assembly Language)
PC Platform

External Sites

Other efforts

QEMU documentation on wikibooks.org
QEMU-Buch / QEMU-Book - A quite versatile book on QEMU, provided in German and English (partly as a google translation), but likely rather outdated nowadays.