The FAA has very specific guidelines for those interested in becoming an aircraft mechanic. The easiest thing to do is to attend an FAA approved aviation maintenance tech school which will guide you through all the things you need to get your FAA certificate to be a mechanic. If you don't want to attend school, there are some things you have to do. You must take an English write/read test and be at least 18 years old. You then have to 18 months of practical experience working with airframes or power plans.
Once you have accomplished the requirements, the FAA will issue you a certificate that gives you the authority to be an aircraft mechanic. Once certified, you can be hired by any airport or aircraft manufacturer as a mechanic to work on aircraft. Most mechanics deal with exterior and internal repairs on airplanes. Today's planes make it easy for workers as there is a computer which tells you what components may need replacement or are not working to optimal settings. This can really help you pinpoint problems as an aircraft is an extensively difficult and complex machine. It is your job to replace and to perform preventative maintenance to make sure the airplane functions properly.
Aircraft mechanic jobs pay very well and there is a lot of job security in this career path. People rely on air travel to get them across the country more than any other type of travel means. Although the aviation industry has had its ups and downs, it will always continue to be a thriving business.