One of the best videos explaining how bitcoin work is this: https://www.youtube.com/watch?v=Lx9zgZCMqXE. It's technical, but allows you to understand a lot about how it works.

Regarding the pay for the mining, there are two sources of income: First are the bitcoins that are rewarded for each new block discovered, but this reward is going to vanish in a few years because the amount given as a reward is halved every 210,000 blocks. So around 2100 there will be no reward left, because the number of bitcoin that will appear is limited to 21 million.

The second source of income for the miners is the fee payed by those who want their transaction added to the blockchain.