Some Shell Basics

There is an excellent book "The UNIX programming Environment" by Kernighan and Pike that can be a very useful book for understanding pipes (redirection of stdin and stdout). It will be very important to understand how 
processes are created (fork, exec and wait) and processes communicate through pipes (stdin and stdout redirection) and also some system calls like dup would be enormously helpful. I can also help in pointing to resources 
as well help in understanding both the file system as well process management system calls. 
sri