When starting the first project in a new language, you have basically two approaches to learning. Either you do a quick Google search, pull together the most popular frameworks and libraries and work your way from their tutorials towards what you want to achieve (top-down). Or you start with the language basics and the standard library and by and by replace your own simple components with more sophisticated third-party components once you know what you're searching for (bottom-up).

Now I'm about to embark on my first serious Javascript project. There's probably as much to know about the language as there is about jQuery, ExtJS and whathaveyou, and I'm trying to decide what to focus on.