You go to steemmonsters.com. You sign up/log in with steemconnect.

Initially you have to buy what's called a starter pack which is 5$. You can pay with $ (credit card) or Steem.

Later you can buy what are called booster packs. A Booster pack contains 5 cards (that are revealed later when you buy them) and each booster pack costs 2 $.

You can also buy single cards on the market.

There are four groups of cards each higher in value:

• Commons
• Rare
• Epics
• Legendary

Then you have the golde version of these groups.