Although learning CAD takes time, Lynda, which is owned by LinkedIn, offers a series of video-based tutorials to help students get started. About.com also has a number of tools to help students learn general CAD concepts.
Udemy offers a three-hour crash course designed to get students up and running with AutoCAD as quickly as possible, and this course can get students to a point where they feel comfortable experimenting with AutoCAD's features and tools. CourseHorse features a search engine that helps students find nearby courses covering AutoCAD and other CAD-related subjects. These courses are especially useful for students trying to get CAD certifications as quickly as possible.