Material to be reffered

i suggest u books of "Upkar Prakashan" and "Pratyogita Darpan" they provides the best material for preparetion of UPSC exams.
for english one needs to practice it by reading newspapers, magazines and books.
the newspaper that is most suitable for CDS is "The Hindu" well in many parts of the country its edition reaches late by a day or two but still it has the richest data and gives the best knowledge about all the current topics.
Current topics must be given prime importance in your preparation ladder. It will be of great importance in your GK paper and of even more importance in your SSB interview.
the most important topics in current affairs for exams is the news that contain historical events happening for the first time (big business deals mainly having an Indian involved in the deal), sports (new world records created in major sports and other records created by Indians and medal tallies and winners of big world events like F1,soccer(uefa & bpl), hockey, Olympics, Asian games, cricket(which most of you will be certainly aware of :-D)), news of Indians abroad (Indian citizens/NRI's becoming diplomats/mp's/politicians/ministers in other countries), circus around the Indian parliament(all political issues and mp's getting involved in controversies), and mainly the diplomats of other countries in India, other countries representative visiting India, headquarters of all UN branches and their dates of establishments with their full forms(ex: UNESCO,UNICEF..) and the most important is receivers of national awards and few international awards.
Its incredibly tough to collect all this information independently the best way out is reading newspaper regularly
so friends just do that it is the best option and will also help strengthen your power over English
so don't wait for the notification or the call-letter...everything will happen in no time....just get started over preparation!
gud luck !

Official websites for guidance.

UPSC(union of public service commision)
www.upsc.gov.in

Indian Air Force
www.careerairforce.nic.in
www.indianairforce.nic.in

Indian Army
www.indianarmy.nic.in

Indian Navy
www.indiannavy.nic.in

what is CDS?

The "Combined Defense Services" Examination or the CDS Exam is conducted twice a year by the Union Public Service Commission for recruitment into the Indian Military Academy, Officers Training Academy, Naval Academy and Air Force Academy. The Notification for the examination is usually released in the months of August and March and the examination is conducted in February and August respectively. Only unmarried graduates are eligible to write the exam. Successful Candidates are admitted into the respective Academies after an interview conducted by SSB (service selection board) followed by the medicals and final results based on all the previously conducted tests.
the eligibility criteria are as follows
educational qualification:
For Indian Military Academy/Officers' Training Academy: Graduation from a recognized university or equivalent.
For Naval Academy: B.Sc. (with Physics and Mathematics) or Bachelor of Engineering.
For Air Force Academy: Degree of a Recognized University (with Physics and Mathematics at 10+2 level) or Bachelor of Engineering.
Age limit:
Indian Military Academy:19-24years
Officers’ Training Academy:19-25years
Air Force Academy:19-23years

Naval Academy:19-22years

Scheme of examination:
All papers are of objective type only. An OMR sheet will be given for each paper and answers have to be marked in it only. There are four alternatives for the answers to every question. For each question for which a wrong answer has been given by the candidate, one third (0.33) of the marks assigned to that question will be deducted as penalty.If a question is left blank i.e. no answer is given by the candidate, there will be no penalty for that question. And no marks would ever be disclosed, in that manner it is a very non-transparent procedure! All marks and selection stages will be kept confidential.
Subject - Time - Total Marks
English - 2 Hrs - 100 Marks
General Knowledge - 2 Hrs - 100 Marks
Elementary Mathematics - 2 Hrs - 100 Marks

Note: For Admission to Officer's Training Academy only English and General Knowledge papers have to be appeared for.

so good luck ladies and gentlemen now there is no looking back!