Books on Hardware

Hello, I'm just getting into PC's and I'm having trouble understanding what some hardware specs are responsible for, for example, voltage on RAM (that was just an example, I already found out about the voltage from one of The Tek videos). Can anyone recommend me a good book on hardware?

Pardon yall for them grammar mistakes, but English is ain't my native language ;)

 

Try some new A+ comptia books. there fairly inexpensive