You can access the classes here.
Over the past few months I have been working with these wonderful folks to produce two InfraWorks classes and one Civil 3D class and I can tell you that Lynda.com is a top notch training company. Everything about them is quality from the facility I recorded in to the highly professional producer that I worked with.
Their service is very affordable as well. For $25/month ($37.50/month if you want datasets) you can get access to all of their courses - and they have a ton. I have used my membership to learn various design products, office products, photography, business, marketing, and even sound engineering (I dabble in music).
If you want to give Lynda.com a shot for 7 days, here's a trial.