For my Linux teaching I use Running Linux by Matt Welsh and few others, published by O'Reilly.
I use it to give me a general understanding of how Linux works, and the very basics of getting the most out of it. I would recommend this book without a doubt, essential.
However, for individual and specific problems which you will face

I would recommend the site
http://www.linuxdoc.org for a comprehensive list of How-to's written by fellow Linux users who give you plenty of advice and tips on the particular topics.