Kernighan, Brian W.; Ritchie, Dennis M; Prentice-Hall; 1988;
ISBN 0-13-110362-8, 272pp.
The improved second edition, covering ANSI C, of the original classic C book coauthored by C's designer, "K&R". Still the best!
Heller, Steve; Academic Press; 1996; ISBN 0-12-339097; 508pp.
The best introductory book on C++ I have seen.
Lewine, Donald; O'Reilly; 1992; ISBN 0-937175-73-0; 607pp.
See
http://www.ora.com/catalog/posix/noframes.html.
An excellent programmer's reference on the POSIX.1 standard. I like this one better than JH's choice.
Zlotnick, Fred; Benjamin/ Cummings; 1991; ISBN 0-8053-9605-5; 379pp.;
$35.95 (USA).
JH: "When I complained about the lack of Section 2 man pages in Linux, somebody told me just to get a POSIX book, because that's what Linux does. I like this book because I'm not a professional programmer and the author gives copious explanations and examples."