Purchase CNC machining books or visit your local library to check out books related to machining. These books cover everything you need to know about CNC machining including common terminology and how to program CNC machines. The CNC Machining Handbook is an important reference that every machinist should own and can help you get started in yourCNC machining career.
Take online classes at a technical college that will let you learn online. These classes have videos that will introduce you to the important aspects of CNC machining including basic principles, tooling used, ways to program machines and basic setup procedures that you can use for any machine. Take classes related to mills and lathes to receive general exposure to the CNC machining world.
Enroll in engineering classes at your local university. You can get a degree in engineering with emphasis on manufacturing. Many universities have CNC machines on campus, and offer classes on programming CAM, or computer-aided manufacturing. Look at technical colleges in your area, as they often offer weekend classes on CNC machining as well. These classes are often a great way to introduce yourself to the world of machining.
Visit a local machine shop and ask to observe one of their CNC machinists in action. This will give you an idea of what daily life may be like, and may give you an idea of how difficult it may be to start a career in this field. You will also be able to see the machines and what you will need as far as tooling to get started.
Get a job as a machinist apprentice. These jobs will give you hands-on experience with these types of machines, and will expose you to the basics of a CNC machining job. You will work closely with an experienced machinist and learn his tricks for better and more accurate machining. He will also help you learn the basics and enable you to obtain a solid foundation for your own CNC career.