hey hello, I hope this question is from entrance exam point of view... As in for NEET.. I'll answer as per that..

Reference books comes in two categories, one in entrance point of view while the other in board level.

For boards level, go for Pradeep's in case of Chemistry and Biology. Even there are more but these two books are very basic and tries to clear all the concepts. For Physics H.C Verma but before that S.L Arora which goes through outline of each topics which clears the mind of doubts.

For a bit higher level, Arihant Publications and Cengage Publications have books focussing on the Entrance level.

For chemistry, you can go refer MTG NEET CHAMPION, GRB BOOKS as well as ARIHANT. For Biology reading NCERT and solving mcqs from Pradeep will be enough I guess.

Go on and buy one but do not forget to devour the NCERT first.