1. Register on www.coinbase.com
2. Click the buy/sell button
3. Make sure you have ticked for "Buy" - Make sure you have ticked Bitcoin - Make sure you have chosen the correct card - Either choose amount in USD / EURO or BTC - Double check everything and make the payment
4. Complete the 3D bank security if your bank requires this. Then wait for the transaction to be confirmed on the blockchain. You can monitor the process in Accounts and Transactions.