The Xilinx EDK is a development environment for embedded system. NetFPGA-10G is largely built upon the EDK, in which modules are organized as pcores and most projects are standard EDK project. Although not NetFPGA-10G specific, the following documents and videos may help you understand EDK concepts and normal practice.
- EDK Concepts, Tools, and Techniques - A Hands-On Guide to Effective Embedded System Design
- Embedded System Tools Reference Manual
- Platform Specification Format Reference Manual
Here is a set of very useful tutorials provided by SILICA.
Base System Builder
A Guided Tour of the Platform Studio
Adding custom IP to an EDK Project
More videos can be found here.