You might check books by W. Richard Stevens: http://www.kohala.com/start/ They are well written and describes the area thoroughly. They even available for free in source form :)
Alternatively you may ask your questions on stackoverflow :)
By the way: a good source for learning *nix-like environment is to use info
together with man
. For example check info libc
to get a pretty decent introduction to system calls with examples, info gcc
gives you GCC docs and so on. After all the C language and UNIX are two siamese twins, they can't exist without each other.