I am looking for a book that discusses the concepts of infinity like the actual infinite and related concepts. Any suggestions?
For a nice introduction to the many different notions of infinity in mathematics see Rudy Rucker's book: Infinity and the Mind. Unlike many other popularizations, this is written by someone who did a Ph.D. on the topic. Rucker goes to great lengths to make the presentation faithful to the mathematics but still accessible to an educated layperson. See this answer for an excerpt on Alephs.