The book bitcoin for dummies can be found here https://www.amazon.com/Bitcoin-Dummies-Prypto/dp/1119076137 . However, cryptocurrency as the concept in itself is not as difficult as some make it out to be. I have a background as a cryptographer and putting it into the simplest form cryptography is nothing more than a pair or series of keys and or codes that interconnect a type of information. To an extent you could compare it to that of a handshake. Nothing can occur prior to the pairing taken place as the information will not be complete.

Mining generates money because it is an easy way to not have to pay people that work 24 hours a day and don't call in sick. The coin is stronger with a stronger network of mines. This doesn't take into account inflation, increase in coin circulation and other things. This site is able to pay people because content costs money and usually sites such as Facebook make millions per day because of user provided content. The only difference is they don't share in the gains or losses of revenue as the company grows or shrinks.