As an engineer, the "required" amount of schooling is generally a bachelors degree. I assume many engineers have an associates degree. However, the position I was hired at required a masters or doctorate. One thing you need to know about most technical fields, however, is that there is no such thing as "enough" education, not only because there's so much to learn, but because you're talking about a moving target.
If you look at folks who are happy and successful in their careers, you'll generally see someone who just can't get enough of it. If you look at anyone in a technical field, they talk, think and listen to anything involved with it, so learning is more or less not only effortless, but irresistible. You think of someone being retired sometimes as thinking, "Whew -- glad that's over. Now I can forget about that stuff." Not a chance. Watch an engineer's face when they see a TV commercial for some new technology and see their eyes go wide. See them attend a movie and they'll leave and talk about how the special effects must have been done and how much computing power they must have needed or criticize the the silly and impractical design of something they saw.
So the answer to how much schooling is typically required for most careers, and the answer is generally, "more".
It will truly depend on the line of work that you want to pursue. There are a lot of people that are very successful at a trade and they only require trade school (in lieu of a formal 4 year university education). If you are looking into a specific field, you must research the educational requirements for that role. For example, if you want to become a lawyer, understand that you will have to get a Juris Doctorate and then pass a state bar exam.
I second what G Mark said. As an accountant you need a bachelors degree and a total of at least 150 credit hours to sit for the CPA exam. There are continuing education requirements as well, and I am required to obtain 80 continuing education credit hours every two years. The above are more of minimum requirements. To be a top performer you will need to stay on top of changes in technology and business developments that impact your clients.