Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.
This chapter covered a lot of ground. The references will help you go into more depth on the Linux file system, shells, editors, and permissions. When choosing a shell or an editor, I highly recommend reviewing their man (or info) pages, as well as their websites.
http://www.pathname.com/fhs—Probably more than you want to know about the new Linux Filesystem Hierarchy Standard.
http://www.linuxbase.org—The Linux Standard Base page.
http://standards.ieee.org/regauth/posix—The IEEE POSIX information page.