Some Useful Books would be:

Universal’s Guide to LLB Entrance Exam (For your General Preparation)
Merriam Webster’s Vocabulary Builder (For increasing your Word Power)
Manorama or Penguin or CSR Yearbooks (For your General Knowledge)
RS Aggarwals Guide to Logical Reasoning (For your Logical Reasoning)

January, February, March, April and May editions of Civil Services
entrance magazines like:
Civil Services Chronicle
Competition Refresher
Pratiyogita Darpan
Competition Wizard
-These magazines will revise your essential GK in a nutshell through
small modules.

MBA Entrance Magazines like:
Chandresh Agarwals MBA Today (FOr WOrd meanings and tests)

Q. I was basically preparing for JEE this year. i just have a few days left to prepare for CLAT. How can i make best use of this limited time period?

I appreciate your efforts towards JEE-The Lord of all Exams. Indeed, science does build up your analytical ability. Why not use it in CLAT?
You have limited time and have to get the maximum returns.
Therefore, if you have a guide book, you could cover theory in brief and jump directly to model papers.
THEREFORE,

Tip #1: Practice Papers heavily- both previous years and/or model papers.
Get your hands on CLAT-2008 model paper.

Tip #2: For Legal GK: get a book devoted to General Knowledge. I know of Manish Arora’s Book on legal General Knowledge. Get your hands on it.
Tip #3: For General Awareness or GK: Get your hands on:
The current and the last 3 month volumes of Civil Services Chronicle, Pratiyogita Darpan, Competition Refresher OR ANY DECENT MAGAZINE FOR PREPARATION FOR CIVIL SERVICES EXAMINATIONS.
These magazines will cover in brief all events of the past one year and carry special sections on Indian Economy, Governance etc. In short, at the news stand, look for magazines having such data and buy them.
Purchase the CSR 2009 yearbook. Its GK section will help you.
Tip #4: Logical Reasoning: Buy a dedicated book for logical reasoning. It should be comprehensive. Practise a reasonable number of questions from each section and cover all required sections. Make sure it contains many ‘passage reasoning’ questions.
Tip #5: Mathematics: Get a decent CLAT guidebook (eg. Universal’s guide). Practice a decent number of problems from it. Maths should not be a problem for you as you are a JEE preparer.
Tip #6: For English:
Reading Comprehension: Use a CLAT Guide
Word Meanings: Try using MBA entrance guide magazines. they have words filled in them, with meanings given.
Grammar: Use a decent grammar book. Since these books are filled with matter, go to sections in them where the CORRECT USAGE of words is given. Be very thorough with correct usage of words. It is the essence of grammar. Look at lists of correct usage sentences (these are also contrasted with incorrect usages) and get an idea of where in the sentence to use a particular word.
Tip #7: Time management:
You have few days left.
Practice all subjects and chapters on a uniform basis. Practice 2 to 3 test papers a day. these will give you a good idea of the paper.
ALSO, get hold of the CLAT-2008 paper IMMEADIATELY.
It will help you a lot, especially with regard to the syllabus.
Also, get hold of a good CLAT guide. Practice less from the questions behind the chapter and more from the model papers. Also, practice each paper in a proper exam pattern. STUDY FROM THOSE SOURCES AND MATERIAL WHICH GIVE ALL THE REQUIRED KNOWLEDGE IN A NUTSHELL- IN A PRECISE AND CONCISE MANNER. Get a hold of the topic by practicing a few questions after each chapter.
Do not lose hope if you only have 9 days left. I know a person who basically prepared for around a week and got into RMLNLU Lucknow. STUDY FOR AT LEAST 10 HOURS A DAY.
All the Best!

Q. Which subjects should I take in my 11th for a simultaneous smooth prep for CLAT??Does the choice of subject really matter?
Anyways i am planning to take commerce with maths…will it be fine?

Ans. Choice of Subject for 11^th and 12^th is relatively immaterial for CLAT.

Commerce with Maths is fine for CLAT.

Even Science and Medical preparation can be done alongside CLAT preparation.

Therefore, choose the subjects you like to most. All you need to give CLAT is 50 per cent marks in the 12^th Board Exam. Which subjects you study will in no way affect your preparation. CLAT preparation can take place alongside any other exam preparation. It is subject-independent preparation.

Q. WHAT SHOULD BE STRATEGY OF SLVING YHE PAPER VIZ WHICH SECTION FIRST AND HOW MUCH TIME TO BE ALLOTED TO EACH SECTION?

Ans. You must attempt all questions, starting with your strongest subject. I started with General Awareness as it was my strongest. You must be very fast. If you are unsure of an answer, go by intuition or mark the option which first came to your mind. Remember, you will have little or no time to return to a doubtful question and think about it. Solve all that you know first. Once you have completed solving, then return to doubtful questions (if you get the time. you will have to be rocket fast in solving then). If you don’t get any answer, then mark all doubtful unmarked questions with any random option (eg. aaaaaaa or bbbbbbb etc.). BUT DO NOT LEAVE ANY QUESTION UNMARKED.You can get at least some marks going by the rules of probability this way. While solving do not stop to think on a doubtful question. All doubtful question should have an option marked. You might return later and change the option, but you may not get the time.