If you're not too familiar with hardware or how computers work at a low level (assembly language, instruction sets, etc), then I would think about reading Code:

If you're not too familiar with hardware or how computers work at a low level (assembly language, instruction sets, etc), then I would think about reading Code: The Hidden Language of Computer Hardware and Software. It starts off with a story of two kids communicating to each other with flashlights in Morse code, and slowly builds up into how a computer works.