Physio is actually the most interesting subject in 1st year for sure but studying it for exams is really a tedious job !
So how to study ? I will tell you my experience for physiology
Guyton is the best book for physiology
But the only problem with guyton is it's style and language and you may not be able to write your papers with it ,but trust me you will definitely not find any better book than guyton for physiology during your graduation .
So I would suggest you to use
Guyton+V.D. joshi/BJ notes.
V.D. joshi is just a question -answere format of guyton ,i choose bj notes over V.D. joshi.
Important chapters like GIT , Reproduction and CVS must be done from guyton ,I personally made my own answere by combining guyton and bj notes ,but trust me it's really tedious job and time consuming !
Exclusively for CNS i won't suggest you to use guyton ,content is directly of PG level and it will be hard for you guys to digest it in 1st year itself .
So use books like A.K.Jain or directly go for answers from V.D. joshi or BJ notes but that won't be worthy ,I used sembulingham for some topics of CNS and then used bj notes to understand them in detail!
Physiology is worth reading but it's more important to revise it from time to time just like for other two subjects !
Daily reading of physiology is must !
Good luck !
~Ojas