There are front-end only jobs (HTML, CSS, Javascript). I imagine these positions would require programming with Javascript as well as some basic familiarity wit

There are front-end only jobs (HTML, CSS, Javascript). I imagine these positions would require programming with Javascript as well as some basic familiarity with Jquery and other front-end frameworks. Some jobs require you to know the full stack - everything from front-end to back-end SQL. And some jobs are for back-end development only - with back-end languages python, java, ruby, or PHP. If you use python or ruby you should learn the associated web frameworks as well (Python+Django and Ruby on Rails being the most notable). It depends on what you want to do. Do you want to code your own websites or work at a dev agency? -- You need to learn the full web stack. Do you want to work for a hip startup? -- you should probably learn a back-end language and a web framework and build a project website with it. I'd recommend either ruby on rails or python + django.