I'm not a web developer, but I've done a fair amount of web development over my 20 or so years of working in the tech industry. The web has been a very convenient way to demonstrate backend capabilities and I've created many web-based demos, visualizations, and developer tools/utilities in that time. Somewhere in the last few years, I think I've learned enough and created enough to say that I'm no longer just a "terrible hack". It helps that the web development community has become more mainstream, there are so many tools and resources. And that is the point of this post.. Getting started with web development in 2015.
This should teach you the fundamentals. As an alternative and for supporting material, I strong recommend you bookmark http://www.w3schools.com/. This site has basic tutorials and its a wonder reference resource.
If you are willing to pay for you lessons and you like to watch videos there are plenty of online learning sites that teach the basics I've mentioned - such as https://www.codeschool.com. I've viewed some of their introductory material and it isn't bad.
While geared towards children, the "Learn Web Development" site I created also takes you through the basics. The lesson culminates with learning a simple hangman web application. I recently export the hangman code to codepen:
Lastly, if you want the big picture on what you need to know to be web developer, I think this video is a good summary: