You read to acquire knowledge, to gain an understanding and to avoid making mistakes, and reading a casino guide is no exception. Reading a casino guide is good, not only because you can find the best casinos, but also to get clarity on what is legal, how the casinos operate legally and honestly, what and which casinos are safe to play at, how a bonus works so that you can withdraw any winnings, and to understand how different slot machines work according to different symbols, how the numbers come randomly etc.
If you read the casino guide, you also have the opportunity to become better at playing. Without fully understanding the functions of the different machines, what the different symbols mean and the like, it is not always as easy to understand why you won on one combination, while not winning on another, or why you get a bonus round and where many free rounds you have. Unfortunately, this is where one of the cases is that practice does not do perfection, and even if you get a better understanding of how the various games, bonuses etc work, we must point out that you can not use casinos as an additional source of income. But all in all, you get a more holistic understanding.