Which are the best and easy books that i should refer for CBSE Class 12(PCMB). Tell me any 1 book of each subject and what to study from it(i.e. derivation, theory, concepts.etc).

NCERT Textbooks are best !!! for class 12[pcmb} and it is affordable.it provides easy  answer with colourful illustrations.

@ shreyas 
you are asking abt 1 book per subject and also what to study from it ?? how is that possible , if u have to study derivation from 1 book and theory from other book m, then it will be 2 books in total .. ryt ?? 
HERE BELOW I AM INCLUDING THE BEST BOOKS FOR CBSE BOARD POINT OF VIEW THAT I FOLLOWED TO GET 96 PERCENT IN BOARD 
PHYSICS 
1- ARIHANT ALL IN ONE ( COMPLETE BOOK IN ITSELF , ) IT HAVE everything , like derivation , past year paper chapterwise , imp question , formula booklet as well as sample paper . 
2- still check it if u are not satisfied with that then go for SIMPLIFIED PHYSICS BY SL ARORA 
they are good for numericals, 
but i could guarentee all in one and askiitian study material and revision note will suffice for physics 
CHEMISTRY 
1- XAMIDEA CHEMISTRY ( VK GOLBAL PUBLICATION ) 
2- ARIHANT CHAPTERWISE BOARD PAPERS . ( FOR QUESTIONS ONLY ) 
3-- MECHANISM IN ORGANIC CHEMISTRY SHORTCUT BY MTG PUBLICATION ( FOR REACTION MECHANISM AND NAME REACTION ) 
MATHS 
1- MATHS BY DINESH PUBLICATION . ( FOAL ALL KIND OF THING ) 
2- R.D SHARMA MATHS ( FOR ONLY INTEGRATION , DIFFRENTIATION ) 
3- LAST YEAR BOARD PAPER MTG PUBLICATION CHAPTERWISE ( FOR SURE ESSENTIAL ) 
BIOLOGY 
1- XAMIDEA BIOLOGY ( COMPLETE BOOK IN ITSELF ) 
2- PREV YEAR BOARD PAPERS CHAPTERWISE ( ARIHANT , FOR QUESTIONS ) 
and also donot forget to read and practice whatever material avaliable at askiitian , they have study material , revision notes , solved board paper , sample paper etc . 
ALL THE BEST ..

How much % did you got in 12^th @umakant and when did u complete your portion and how did u studied. I am eager to know. Are you too a askiitian student as i am …...........?

@ shreyas 
i got 96.47 percent from 12^th cbse , and for that hard work required , i am sure of that . 
and the main thing is confidence level , donot ever think that toppers are made with some diffrent supernatural power by birth , they are also the same brain as u have , but the thing come into play when u use your brain effectivly . 
just by regular practice u can acheive that , and keep 1 example – sachin tendulkar is master in cricket , still he is doing practice dAILY , THAT was my ideal and by that i also practiced everything each day . 
and in organic u required regular study , 
take good care of your health , thats the only resource u have to help u to do hard work . 
AND YES , I WAS A ASKIITIAN STUDENT .. 
they have helped me so much . 
 

@umakant …..ok thanx. how much time should i study daily? and till what time should i complete my syllabus?? Did you refer the same books as prescribed above???