As Sir John Gielgud once said, You could never learn to act or to be a good actor from books, or (my addition now) by following someone online or getting tips from facebook or the internet. However, it is how you decide to utilize the information that you get that determines whether you grow or not.
If you get the information and then go home and sit on your laurels the information will not help you. But if you take the information and use it to transform yourself, and work as hard as you can, then you will see the improvement.
The funny thing is that those actors who do not read and do not google and do not seek out information on facebook, twitter and other online platforms, do not stand a chance to grow as much as those who do, however, searching for information alone does not guarantee growth.
You need to search for the information and upon finding it you then need to use it to the best of your ability. The most important exercise in the growth of an actor is rehearsal. You have to rehearse even when you do not have a show coming up, rehearse just to sharpen your instruments, rehearse so that you can be a better actor, rehearse just to be able to test the material you gleaned from books. An Actor Prepares, An actor rehearses.
The world of acting is dynamic, it is not stagnant, it changes almost every decade, sometimes even less. It therefore becomes important for an actor to keep up with the times and the changes, and then take whatever he/she can, and implement it into their own vocabulary of instruments.