You can give all access points the same SSID and encryption key. It doesn't hurt anything. Guest devices should then connect automatically to the strongest signal. Assuming everything is wired up right. You could have all floors connecting to a single high speed internet connection.
Although depending on the size of your hotel. You may want a professional networking company out to setup a network with something like Ubiquity access points in the ceilings and isolate your network from guest devices. Plus you may need something like a load balancing router and QoS to balance traffic and have a fail safe if one ISP goes down.