Guys, can you suggest me the names of some good books for the preparation of Karnataka Administrative Services exam????

Yes sure, here I am suggesting you the names of some good books for the preparation of Karnataka Administrative Services exam:

General Science: For preliminary exam there are books which cover all the topics for KAS.
Tata Mc Graw Hill
Spectrum
Sparda Spoorthi
There are many other books which cover all the topics of KAS preliminary exam.

Indian History :
India Struggle for Independence by Bipin Chandra
Modern India Spectrum publications
NCERT Books ( XI & XII )
History of Karnataka by Ranganath
Karnataka Handbook.

Indian Polity :
Indian constitution DD Basu
Indian polity by Laxmikant

Geography :
Spectrum Publication.
Geography of Karnataka
NCERT books

Indian Economy :
NCERT Books ( XI & XII )
Pratiyogita Darpan
Current news in Economy.

Mental Ability :
Quantitative Aptitude by R.S. Aggarwal

Science and Technology and Environment:
Thursday issue of The Hindu paper.
Science reporter.
Other Magazines on science and Technology and Environment.

Current Affairs: Some magazines and Newspapers
Prajavaani
The Hindu
Competition WIZARD
Sparda Spoorthi
Sparda chaithra.