I've been involved in political activism working on the Obama campaign and now that that's succeeded I've been trying to educate myself for the future to best apply my efforts to a cause. In my research I came across a book called "Thinking Big" (great video for it here:
Thinking Big) that is like the cliff's notes for the progressive movement - it's published by a group of progressive organizations, some of the best in the country - and written by leaders of these groups. Highly recommended - no matter your political affiliation - as it's a dense read of solutions to current crises and I feel a more informed citizen having read it.