Inside PE format

The PE (portable executable) format is file format for executable, dlls, object code, of windows OS.
Following of the papers/links that explain in clear way this format.

Portable Executable;
An In-Depth Look into the Win32 Portable Executable File Format;
An In-Depth Look into the Win32 Portable Executable File Format, Part 2;
Class to access PE;
Peering Inside the PE: A Tour of the Win32 Portable Executable File Format;
THE PORTABLE EXECUTABLE FORMAT;
Exe file format with offsets rather than explanations;
Inject your code to a Portable Executable file;