[richm44]

I'd recommend this book instead 'The Linux Programming Interface' http://man7.org/tlpi/ it's a lot more recent and the content is excellent, though it's not a free download. The author is also the maintainer of the linux man pages.

[jaimehrubiks]

Well I don't think it is so much better, I is very usefull but it seems to my more like a manual than a book