What is mining? It is the process of using computer power to verify CKB (CKByte) transactions on a blockchain and miners are given a monetary prize for contributing the computer power.
Real-time hashrate on CKB Block Explorers
Real-time Profitability on Whattomine.
CKB mining pools: miningpoolstats
Stratum protocol standard for mining pools
How to Mine Tutorials
How to get started with the CKB DAO
Security is the most important thing for a permission-less blockchain with the goal of being a global settlement layer, and CKB is secured by proof of work consensus algorithm. It's not saying PoS won't work, it's just as a new chain, CKB chose to use a consensus it's more sure of the security impact.
Discussions about PoW vs PoS:
PoW vs. PoS
Decentralization and Security