Tell me to prepare thermodynamics
First make sure on basics and formulas of the concept, reffer the book and choose for best and make use of it. In my view
Engineering Thermodynamics by P.K Nag.
Thermodynamics (SI Units)
Thermodynamics: An Engineering Approach by Yunus-Cengel-Michael-Boles(SIE)
Principles of Engineering Thermodynamics, SI Version (WSE)
Engineering Thermodynamics by M Achyutan.