This is the first lesson that will help you to get started with Grasshopper. In this video you will learn about the Grasshopper Canvas, and how to create your first Grassopper definition. This is the first episode of a 13 video introduction series, Grasshopper Basics with David Rutten.
Since grasshopper is the new age in architecture now, DesignReform made a collection of resources on their site. Be sure to check it here: 10 Online Grasshopper Resources.
In this video tutorial we will continue with the introduction to grasshopper. Rather then using numbers we start to make points and get a sense of how the components make geometry.
This is the thrid video from the 3-Day Workshop at Virginia Tech. It covers how Grasshopper handles data matching amongst many other things. Fair warning, they were testing the fire alarms during the recording and you can hear them going off around minute 5 and minute 10, pretty funny.