Cardano(ADA)’s staking comes out in November and there are a few details you need to know. You need to have your coins in a Yoroi or Daedalus Wallet before the snapshot, but after the snapshot is done, you can move them back to wherever you transferred in from. The staking percentage will be about 12% and will not depend on he size of the staking pool. The coins on the testnet will not be spendable but you will be able to move them back onto the mainnet once everything is done.