Going to Bulgaria

I fly today at 5 o'clock to Varna, and then I've got no idea where I'll be staying (?). I'm looking forward to it, but I'm not really sure what to expect there. I've set up my phone so I can use it there, but vodaphone charge £1.69 per minute for calls in Bulgaria, so I might get a sim card out there. A few useful links I might need: Mobile Phones Map of Varna * Map of Bulgaria