How can I learn Javascript for web development (professional advice)?

I want to develop web applications for my own needs, or work for software companies.

Here is my story: I have developed a couple HTML, CSS templates for < 500 price for various clients which included a bit of JS logic. I have been into web stuff for two years but I could not call myself a web developer since I have never read any book or finished a tutorial of some sort. All I have done was googling to solve problems. At the moment I am learning Ruby on Rails thus it motivates me to learn Javascript properly to be a recognizable figure in the business.

How should I start learning Javascript for web as I have never done it the right way? I am starting to see that freelancing does not provide me with enough experience in JS therefore I am seeking for a professional advice. All I want is to have enough knowledge to get a job as a student, and easily program moderate difficulty web apps.

Thank you!