We have talked about Google Ad Manager here somewhat often, we even use Google Ad Manager to serve the ads on this site.
Now that more and more publishers and webmasters are using this ad serving tool, Google needs help with aiding webmasters and publishers in setting up and trouble shooting. Right now, there is a very useful Google Ad Manager forum that people can use for help. But Google just announced a certified Ad Manager program. There are currently four companies listed as certified consultants. I assume if you want to be a certified Ad Manager consultant, you would need to contact Google.
Forum discussion at DigitalPoint Forums.