CAD is a professional drawing software, its function is very powerful, learning CAD is a very need method of things.
Learning software CAD, you must first understand the software, know the general framework of the software structure, use.
The best motivation for learning is interest. So the joy of CAD must be found in life is a very important factor.
Buy a primary textbook to the book, it is best to have a DVD, while watching to learn faster.
You can find some websites on the Internet that provide free instructional videos, which are also very practical.
More practice is the root and direct cause. A lot, a lot of patience, and you'll soon learn.