the hotels mentioned in Alistair's reply are all located within TIKAL National Park.... If you want to see the ruins, this is the best alternative...in the price he mentioned, some hotels include breakfast plus the Excursion/guide to see the Temples and Pyramids.
Prices differ if you go in high season or in low season (Low season coincides usually with the rainy season. There is a direct flight from Guatemala Airport to Santa Elena/Flores Airport, which is 1 hr from TIKAl. Ask the hotels about shuttling you from the airport. For more info about Guatemala see www.medicaltourismguatemala.com You will love Tikal!

There are a few places nearby, including Hotel Tikal Inn (US$140-$280), Hotel Jungle Lodge (US$145-$230), and Jaguar Inn Hotel (US$40-$90). These aren't in the ruins, though, as those is protected national parkland.