I am attempting to find documentation of the psd file format so I can read in a .psd and then save out the individual layers as files, along with do other modifications. Doe
The PSD file format specification as written by Adobe is here;
http://www.adobe.com/devnet-apps/photoshop/fileformatashtml/
Last update: June 2012. As far as I know this is the best available source about the PSD file format even there are few mistakes.
First I recommend starting by dividing PSD into blocks.
Enjoy!