I highly recommend this issue of Larry's newletter to forum readers. It is full of direction, resources and suggestions for improving your workflow and taking you to the next step as a web developer.
Regarding responsive web design resources, Ethan Marcote's book Responsive Web Design is the best resource for first getting started with rwd. After that I would suggest jumping in and converting / building a responsive site.
Frameworks - JQuery Mobile is worth getting to know and Pro JQuery Mobile is a decent resource for getting started.