The
Slackbook is very good on basics, such as permissions, file structure, and the like. I bought a copy and read it through.
Garrels's
Introduction to Linux. This helped me more than any others when I was starting out. Also read it through, and it's frequently updated.
Linux, the Complete Reference. It's more like a manual than a teaching document: a good reference, but not something to sit down and read through. I have an earlier edition; the best comparison I can make is that it's like a compilation of man pages.
About dot com has a good
online intro to Linux. It's oriented towards Ubuntu, but the information is solid and accurate.
I would recommend downloading Garrels, printing it out, and reading it through. It's more comprehensive than the Slackbook.