GETTING THERE:Until Oct. 31, Eastern and Pan Am are offering a $493 round-trip midweek excursion fare connecting through Miami to Guatemala City, with no advance purchase necessary. Weekends and high season (Nov. 1-Jan. 15) fares range from $508 midweek on Eastern to $604 weekends on Pan Am.

Eastern, Pan Am and Guatemala's Aviateca airline offer package tours from Washington that include hotels and visits to Tikal, Antigua and Lake Atitla'n.

GETTING AROUND:Car rentals are expensive, about $235 per week at the major hotels, including mileage. Local buses are more picturesque than comfortable but are very cheap. Cabs in the city average $2 to $3 per ride.

Tours are easily arranged in Guatemala City, with Agencia Panamundo specializing in Tikal arrangements.

WHERE TO STAY:In the capital, luxury hotels with pools include the Dorado, the Fiesta and the Camino Real, all near the U.S. Embassy, at $50 to $60 per day for a double. The Ritz Continental, right downtown, also with pool, is comfortable at $30 to $40 double. Gringos often lunch at the Pan American Hotel, which is clean and basic at $20 a night.

In Antigua, the Hotel Antigua runs $40 double, the Posada Don Rodrigo, $20. In Panajachel, the Hotel Tzanjuyu is $22 single, $38 double, and the Hotel Atitla'n is $55 double and has a private beach. In Chichicastenango, the Mayan Inn is $55 double, with beautiful antiques and gardens, and the Pension Chuguila costs $6 per person plus $1 to have a fire built for you. In Tikal, there are the Hotel Jaguar and the Tikal Inn, both $35 to $40 double, and the Jungle Lodge at $30 double.

PRECAUTIONS: For health precautions, see the Fearless Traveler column on Page E1.

INFORMATION:The Guatemalan Embassy here in Washington has a helpful tourism attache', Maria Landis. Or contact the Guatemala Tourist Commission, Box 144351, Coral Gables, Fla. 33114-4351, (305) 854-1544. In Guatemala City, the Guatemala Tourist Commission (Comision de Turismo) can help plan your visit.