Good ol' boy is an Americanslang term that can have both positive and negative meanings, depending on context and use.
The term can be used for well socialized men who live in rural and generally Southern areas. If a man is humble and well thought of, he can be referred to as a "good old boy", regardless of his age. It is commonly applied to men with a family of generational wealth or prestige, or overall moral behavior.
It can be used as a pejorative term, referring to someone who engages in cronyism among men who have known each other for a long period of time. Collectively these people are referred to using the slang term, good ol' boy network (also known as an old boys' club).
^The American Heritage Dictionary of the English Language (4th ed.). Boston: Houghton Mifflin Company. 2009. p. 757. ISBN0-618-70172-9. OCLC535837910. n. Slang: A man having qualities held to be characteristic of certain Southern white males, such as a relaxed or informal manner, strong loyalty to family and friends, and often an anti-intellectual bias and intolerant point of view.