Crash Course on the Filesystem Hierarchy Standard @ http://sysadmincasts.com/episodes/12-crash-course-on-the-fil...
Crash Course on Common Commands @ http://sysadmincasts.com/episodes/13-crash-course-on-common-...
Crash Course on Man Pages @ http://sysadmincasts.com/episodes/19-crash-course-on-man-pag...