Group representation theory references
For a concise, comprehensive, and quick overview of finite group representation theory over the complex number field, I recommend the notes on group representation theory by Prof. Hua-Chieh Li from the Department of Mathematics at National Taiwan Normal University. Link: https://math.ntnu.edu.tw/~li/note/REP.pdf. Prof. Li's website: https://math.ntnu.edu.tw/~li/
The textbook Representation Theory of Finite Groups by Benjamin Steinberg offers a comprehensive and approachable introduction to the representation theory of finite groups. In addition to establishing a solid theoretical foundation, it explores applications to finite group theory (for example, Burnside’s theorem) and combinatorics. Moreover, its treatment of the connection between group representations and Fourier transforms on abelian groups provides an inspiring perspective on studying representation theory. Springer book link: https://link.springer.com/book/10.1007/978-1-4614-0776-8