As an often-security-engineer and an individual that has been working on large networks for quite a while, dealing with DDoS, or the threat of DDoS is a well traveled path. Recently I was invited to discuss some of the basics of DDoS mitigation on the Network Collective Podcast. This was a really fun and insightful chat with a wealth of great information for engineers and operators of any skill level.
 

Ep38 – DDoS Mitigation from Network Collective on Vimeo.
 
As mentioned in the cast, there are some good, free resources out there for black hole routing.
GRnet firewall on Demand
BlackHole Routing Basics
Using BGP FlowSpec slides from NANOG