Official websites

cardano.org

Cardano's official website

iohk.io

Input Output Hong Kong (Global)

cardanofoundation.org

Cardano Foundation

emurgo.io

Startups and enterprises solutions

Wallets and block explorers

daedaluswallet.io

yoroi-wallet.com

explorer.cardano.org

seiza.com

Official wallet (full node)

Official wallet (lite)

Official block explorer

Official block explorer

Pools rankings and statistics 

pooltool.io

adapools.org

pegasuspool.info

adastat.net

Market caps, volumes, etc.

coinmarketcap.com

coingecko.com

Exchanges

binance.com

pro.coinbase.com

huobi.com

hitbtc.com