If you want to learn about the fish that you keep, the best way to do so is simply to watch them. There are no videos, blogs, or books that will provide you as much information about the behavior of your fish as your own eyes.
If you will take 30 minutes each day to watch your fish, you will be amazed how much you learn. This is especially true if you keep breeding pairs or colonies. Gaining any understanding of your fishes’ behavior requires that you see your fish interact with conspecifics and other species. It also requires seeing how males and females of the same species act around each other. Same can be said when they spawn and how they behave as parents.
The range of behaviors you can witness is enormous. I promise if you watch your fish, you will witness behavior that both surprise you and fascinate you. If you’ve heard that each cichlid has its own personality, it is absolutely true. Yes, each species has common behavioral characteristics, but each fish is different. Watch them!
While you’re at it, watch your fish with tank lights on and with tank lights off. Their behavior will vary with the light. Even though my tank lights are only on about two hours a day, my fish much prefer the tank lights off. They are more out in the open. Of course, if you have little to no cover, your fish have no where to go. Nonetheless, simply witnessing disparate behaviors in various light can be enlightening.