manzur

I would recommend you course from NYU: http://pentest.cryptocity.net/

It covers most modern aspect of software security.

It depends on the job you're applying. But to say learning how to solve changes your thinking about problems(any problems) and makes you better and faster solver. For just passing job interview you can check Skiena's Algorithms design. That said I highly recommend Topcoder, especially their cookbooks contains valuable information on very rare topics.