I'd suggest Javascript: the good parts, and then the traditional "Take a small page and recreate it" trick until you're ready to just start a project that interests you. Start with bootstrap to lay it out, and go deeper as you need to. Make it into responsive design. Put some touch events in.
jQuery really does smooth out a lot of the cross-browser incompatibilities, but it doesn't excuse you from knowing javascript. Javascript: the good parts is old, but still a good place to start.
To cement your JS skills, do the project in node.js. I think that really helped cement how I think about JS, and it's not too far out of the way for a backend developer to understand, callbacks aside. (Using a noSql store will help in this environment, as there's no great SQL ORM solution right now and your purpose isn't to get bogged down there.)
As mentioned, Mozilla Developer Network is one of the best documentation sites.
From there, you can turn your jQuery site to a backbone or ember or angular solution to see how that differs. Don't bother with all of them. :) If you can do all that, you're going to be in pretty good shape.