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

http://www.youtube.com/watch?v=STGiqlBRVms

http://www.youtube.com/watch?v=Veut_iOtTv0

A Guided Tour of the Platform Studio

http://www.youtube.com/watch?v=ZBSF2x482r4

http://www.youtube.com/watch?v=HA4qceUvZhQ

http://www.youtube.com/watch?v=MbVwNGGzuxE

Adding custom IP to an EDK Project

http://www.youtube.com/watch?v=MC1amstP_8A

http://www.youtube.com/watch?v=WYOQpqlEY94

http://www.youtube.com/watch?v=DkjVXeqRKjE

More videos can be found here.