Some people are academically inclined while others are superb craftsmen. Learning a trade can be an invaluable life skill which often can become a lucrative profession. If you haven't made it through high school nor have the inclination to obtain a General Equivalency Diploma, fret not. There are hundreds, if not thousands, of trade schools that will train you in the trade of your choice without a high school diploma or GED. Many require you pass, at minimum, a proficiency test before they will accept you and some will require you obtain a GED while enrolled in technical college.
Start your search close to home, unless you have a desire to relocate. If you want to move to a specific area, you'll want to contact the trade schools in the area where you would like to move. Presuming you have a particular vocation in mind, local trade unions can be a good place to start. Call or visit the local union shops and ask for any knowledge they have regarding trade schools in your preferred area of occupation.
Contact the admissions offices of local community colleges that offer training in the profession of your choice. Usually, they are non-accredited schools. For example, the North Georgia Technical School in Clarksville offers truck driving and welding programs to non-high school graduates and those that never obtained a GED. The school requires you to pass a proficiency test before it will accept you to its truck driving school or its welding programs (the only two trade offerings at the school). For admissions to the truck driving program, which is an 11-week program, you need a relatively clean driving record (maximum of eight points on your license over the prior seven years) and no DUI convictions, in addition to the proficiency test. (See references). You can apply online. The welding program is two semesters, or six-months, long.
Check your local library for books like "Construction Book Express," a trade and vocational school directory for those starting in the trades and continuing education opportunities for those already working in various vocational fields. The book lists more than two hundred institutions organized by state. There are numerous other similar books that the guidance office of local community colleges may have or can direct you to. Some of the technical schools require GEDs while others don't. You'll have to contact them to determine their prerequisites. At worst, the schools may be able to guide you to other technical schools in the area that don't require GEDs of high school diplomas. The book is also available online.
Go to the Vocational Information Center on the Internet. It is by far the single most comprehensive resource available. It literally lists all the trade schools from A to Z, from Aboriculture to Zoology. The site even provides an occupational outlook. The site was updated in 2011 so it contains the most up-to-date information on the job prospects for thousands of technical occupations --- many professions you may not have even considered, heard of or know anything about. Again, the admissions requirements vary so you will have to contact the specific technical school if admission requirements aren't listed on the site of the school you want to apply to.