It's a test for most union trades. To those interested, call the union hall where you live. So, it's usually a test, and a interview. The interview counts for 1/2 of the hiring process. The test is usually an 8th grade, or high school equivalency test. It's not hard, but in certain high paying markets, like San Francisco, a 1000 guys might show up to take the test, so you need to get most questions right.

Once you get into the union, it's kinda a cake walk. You can achieve a middle class income, health, and retirement.

It wasn't for me, but a lot of people like it.

(answering the top question. I never wanted to do what my father did. We had a strained relationship the minute I stopped agreeing with him. Even as a kid, I loved my father, but didn't want to be like him in any way--including career.)