The official currency is Nuevo Sol (S/.), the sub units are in cents "centavos"). You will encounter the following small coins:0.10, 0.20 and 0.50 cents, and larger coins of: 1, 2 and 5 Soles, and bills of: 10, 20, 50, 100 and 200 Soles.
In Peru one can legally hold and exchange any internationally recognized currency, and it can be exchanged in banks and exchange bureaus which are everywhere. There is no fee for exchanging currency, and there is NO official exchange rate: one can usually get a slightly better rate in exchange biureaus rather than in banks.
In the airports there are offices of exchange and banks that will change your currency at your arrival to a city.
In commercial areas of each city you will be able to locate houses of exchange and banks. In some cities, especially in Lima, you will see people dedicated to change currency on the streets, which are identified with a special vest and an identification card.
The commercial establishments are not obliged to accept any foreign currency which it torn, dirty, or which they suspect of being false or which they feel they might have trouble changing at a bank later on. Most establishments in tourist areas will accept payment in North American dollars.
The Universal Currency Converter
Peru has a modern bank net that offers all the services with high technology. These banks have their main offices in the city of Lima, and they usually have a wide net of branches in all the cities of Peru.
At the banks´ offices, or in certain public places will be easy to locate automatic cashiers, associated to the main credit cards, in which you will be able to carry out retirements of money, from your own bank account or of credit cards.
That is the case of the chain of automatic cashiers of VISA, Visa Electron, Visa Plus, etc