The money in Guatemala is called the Quetzal. There are eight different denominations: 1,5, 10, and 50 cents and bills of 5, 10, 20, 50, and 100 Quetzales.
Where to exchange money? All banks are open to the public from Monday through Friday from 09:00 to 17:00 (and some banks offer service at external windows until 19:00). Saturdays banks are open from 09:00 to 13:00. Money exchange is also available through many hotels and travel agencies and at the airport. Be carefull in exchanginf maoney on the street. You might get a higher excahnge rate, but beware, non friendly eyes might be prying your business.
All major credit cards are accepted in Guatemala. Teller machines are available in most cities.
Tipping is not required. In eating establishments that provide an official receipt, there is generally a 10% service charge. Some restaurants indicate that tip is not included and depends on the customer to add it for the service and quality of attention received. Keep in mind that many waiters work only for that day and their "salary" is the amount of tips received during the day.
Tipping in hotels and of guides in customary, and depends on the good will of the customer. If you are driving a car and park it on the street, someone will come up to you and offer to watch your car. This price you pay for this “service” should not exceed Q10.
You can bargain with sellers. Foreigners get a marked up price on souveniers and gifts purchased at markets. So, be polite and discuss the price with the seller. In good terms you will get a reasonable price.