Hi ,
Can any one send me the best unix book to start. Actually i know the very basic but i need to learn in depth.
Please send me the pdf or link.It would be very helpful if you send ASAP
Go through these ..
http://www.unix.com/answers-frequently-asked-questions/13774-unix-tutorials-programming-tutorials-shell-scripting-tutorials.html
I will add that to answer this question, one must first know how he/she best likes to learn. Books come in many flavors - examples explained, complete listing of commands and every possible switch setting, starting at very basics, etc...
Depending on how you want to learn, that will set you on a path for appropriate resource materials.