Per previous discussion and one recent meta question the books seems to be the haven for that kind of question. The tag needs a revision of all its questions and we should check whether they are good or not for the site.
Below I will leave a list of questions to review.
Recommended reading to better understand Unix/Linux internals closed per discussion on chat
What is the best book to learn Linux system programming? also closed.
Good introduction to Subversion for inexperienced users? [closed]
Mono book recommendations [closed]
Good free intro to Ubuntu? [closed]
Looking for an old classical Unix toolkit textbook [open and should remain so, this one is a very specific question since it is asking for one book in particular]
good unix troubleshooting book [closed]
What unix certifications are available? Are there any self-taught? [not about books or learning material]
What do all the pictures on the front of the "Unix and Linux System Administration Handbook" represent? [Should be closed as a dupe of the one below]
What are all the items on the cover of the "Linux Administration Handbook"? [open and on topic(ish) I guess. Not a request for learning material in any case]
Stuck between these two books? [closed]
What is the best book every Unix or Linux user should read? [closed]
Plan 9 from Bell Labs book [closed]
Books/Resources which explain TCP/IP kernel implementation [closed]
Book or online article on analysis and tuning Linux system performance [closed]
Recommendation of books to setup and admin a web server in Linux [closed]
