When you get off the international airport in Prague, the only mobile company at the airport is Vodafone. They do not offer limited prepaid SIM card plans, so do not get your SIM card there. Instead, go to any cigarette shop, newsstand or Vodafone outlet in Prague city to purchase a prepaid SIM card. The prepaid SIM card plan that I am using right now is 349CZK per month, with 3GB data, unlimited SMS and free incoming calls.
Once your purchase the prepaid SIM card, connecting the phone to the network is very easy. Simply follow the instruction on the packaging and you’ll get connected within 15mins.
To top-up credit to the account, go to any Vodafone outlet in various shopping mall. I always go to the Vodafone outlet at Palladium, because the sales person is very helpful.