This is the first video in a series that will cover the use of Scapy.  Many of the examples in this tutorial are picked from the SANS SEC 567 Power Packet Crafting with Scapy.  If you find that Scapy does not have a particular function/module to accomplish what you want, you can write your own module.  The best place to look for help on how to do this is: http://dirk-loss.de/scapy-doc/build_dissect.html