recent post at SWTP focused on a quick, free way to get your Freud learned. The resource: AllPsych.com. Have you poked around there? What the site really amounts to is a free study guide for the social work licensing exam. Developmental theories? All there. DSM-IV? Yep. And on and on. The Psychology 101 section alone contains a huge chunk of what's worth reviewing for the exam.
Of course, social work isn't psychology and psychology isn't social work. No one's suggesting you limit yourself to this one resource. But as you're putting your study materials together, you could do much worse than digging into All Psych...some practice tests (e.g., SWTP)...and, of course, the NASW Code of Ethics. You'd be off to a very good start.
UPDATE: Here's a free study guide (actually designed as a study guide for the social work exam) from SWTP.