Documentation
From Openembedded.org
Documentation that relates to OpenEmbedded.
Yocto Project Manuals
The most up-to-date manuals relating to OpenEmbedded (in particular, the new OpenEmbedded-Core) is the Yocto Project documentation, in particular the Quick Start Guide, Development Manual and Reference Manual.
See the Documentation section on the Yocto Project website for links to all the manuals.
OpenEmbedded Manual
The OpenEmbedded Manual (pdf) (html single-page) is also available but is quite out of date. Much of its content may still be applicable however.
Bitbake Manual
The Bitbake Manual is in need of update but its content should still be applicable.
Other
Many of these are out-of-date:
Articles about Openembedded:
Guides and HowTos: