This is one subject which has so many formulas to learn by heart. From GATE 2016 governors and gyroscope were two new subjects added. Although very basic question like just put the value and get answer type were asked in GATE 2016. So overall its easy subject and doing variety of objective problems is very essential. Theoretical part is less and more of numerical subject. You can study from notes or book, and I have seen that notes go exactly like Theory of Machine book By SS Ratan. There are few tricks that you may not find in book, you will come to know when you do objectives.
For Vibration you can even refer to your local book for semester, just see formulae and solve last year GATE questions.
Do I need to read book?
For those who are preparing on there own book is quite essential. Since in the notes there are many topics which are not explicitly explained so in order to understand the concept its necessary to have a reference book. Please note that never ever use local author books which students use to pass university semester exams they will never help. Always follow standard textbooks.
Those who are in coaching institutes who don’t get much time to study from a book they may prefer not to but in case of important topics or confusions books are the best refuge.
Which book to refer?
Its always preferred to read book that you have already studied during your BTech. In case you didn’t read any ???? like most of the engineers.
Following are the books that i would recommend-