These are some of the e-books you can refer, if you are going to prepare for the Gate for Computer Science.

Name	Author	Link
Introduction to Algorithms, Prentice Hall India.(2nd Edition) And its solutions	Corrman	http://rapidshare.com/files/60176661/Algos.zip
Introduction to Automata Theory, Languages, and Computation (2nd Edition)	John E. Hopcroft	http://rapidshare.com/files/60176662/autoUlHop.zip
Modern Operating Systems, 2nd Edition, 2001-02	Andrew Tanenbaum	http://rapidshare.com/files/60176666/MOSTN2.zip
Compilers 1986-01	Alfred V. Aho	http://rapidshare.com/files/60176664/Coahul.zip
Database Systems Concepts, 4 edition	Abraham Silberschatz Henry F. Korth S. Sudarshan	http://rapidshare.com/files/60186128/DBko4.zip
Computer Organization and Architecture	William Stallings	Coming Soon

To open djvu files use this software.

http://www.lizardtech.com/download/dl_options.php?page=viewers