Visitnig Peru and Cusco you will need the next information:

Cusco Climate
Weather can fluctuate from 40 degrees to 85 degrees between Cuzco and Machu Picchu. You need to were layers to ad or removed portions depending on weather conditions. A rain poncho is a must (light). Machu Picchu's high season is during the "dry" season that runs from June through October. The low or "wet" season typically runs from November to April. January, February and March are summer months in Peru, while June, July and August fall in the winter. It is recommended to visit the ruins during the dry season (even though it might be a bit cooler).

Inca Trail Closures
Typically, each year some sections of the Inca Trail are closed for maintanance during the month of February. Also, there are alternative paths at Km. 82 Piscacucho, which includes Patallacta, O'ente, Paqaymayo Bajo, Chachabamba, Wiñayhuayna and Machu Picchu. No overnight at Wiñaywayna.

Immunizations
Consult your doctor. The Centers for Disease Control and Prevention recommends several vaccines for travelers to Peru, as appropriate for your age, your health status and other factors. The vaccines are: hepatitis A or immune globulin; typhoid; yellow fever; booster doses for tetanus-diphtheria and measles; and, in certain instances, hepatitis B and rabies. The CDC says the tourist areas of Machu Picchu are not a risk for malaria, but risk exists in other areas of Peru. For more information, visit the CDCUs Travelers Health site on the Net at http://www.cdc.gov/travel/.

Altitude Sickness
Allow time for your body to adjust to the high altitudes of the Andes, where the air is thinner and the amount of breathable oxygen decreases. Typical symptoms include headaches, nausea and insomnia. During the first 12 to 24 hours at high altitudes, particularly upon arrival in Cuzco, you should rest and not eat big meals.

What to Bring
A fleece jacket with layers that can be removed if too hot. Long-sleeved shirt and long pants to wear while outside whenever possible, to prevent illnesses carried by insects (e.g., malaria, dengue, filariasis, leishmaniasis, and onchocerciasis) or plants. Insect repellent containing DEET (diethylmethyltoluamide), in 30%–35% strength for adults and 6%–10% for children. Travelers who are not staying in air-conditioned or well-screened housing should purchase a bed net impregnated with the insecticide permethrin. (Bed nets can be purchased in camping or military supply stores.) Over-the-counter anti-diarrhea medicine to take if you have diarrhea. Iodine tablets and water filters to purify water if bottled water is not available. Sunblock, sunglasses, hat. Prescription medications: make sure you have enough to last during your trip, as well as a copy of the prescriptions)

Electric current
220 volts. 60 cycles. Major hotels have special 110 volt outlets in bathrooms for their guests; some are marked exclusively for the use of shavers.

Tipping
Most restaurants automatically add a 10% tip (service charge), however, some do not. The total tip should be about 15%. Porters should be tipped US$ 1.00 per bag. Taxi drivers usually do not expect a tip.

ENTERING PERU
Tourism
A valid U.S. passport is required to enter and depart Peru. Tourists must also provide evidence of return or onward travel. U.S. citizens do not need a visa for a tourist stay of 90 days or less. U.S. citizens remaining in Peru more than 90 days must pay a monthly fee to extend their visa for up to three additional months, for a total of six months. U.S. citizens, including children, who remain in Peru over six months without obtaining a residence visa will have to pay a fine in order to depart Peru. Visitors for other than tourist or family visit purposes must obtain a Peruvian visa in advance. Business visitors should ascertain the tax and exit regulations that apply to the specific visa that they are granted. U.S. citizens whose passports are lost or stolen in Peru must obtain a new passport and present it, together with a police report of the loss or theft, to the main immigration office in the capital city of Lima to obtain permission to depart. An airport tax of $25 per person must be paid in U.S. currency when departing Peru. There is also a small airport fee for domestic flights. For further information regarding entry requirements, travelers should contact the Peruvian Embassy at 1625 Massachusetts Avenue, NW, Suite 605, Washington, DC20036; telephone (202) 462-1084 or 462-1085; Internet http://www.peruemb.org; or the Peruvian Consulate in Chicago, Houston, Los Angeles, Miami, New York, Patterson (NJ), San Francisco, or San Juan.

Student/Business/Work Visa
If you come to study, on business, or to live in Peru (working either in the private sector or on government contract), you should apply either to a Business or Working Visa.
You may obtain information at:

Where to go:
To obtain an extension of a tourist visa, to apply for a work visa or a resident visa, you should go to a Peruvian Immigration Office.

Exiting Peru
Make sure not to loose the Immigration form you were given at the time you enteredPeru as you need it when you leave the country.

A departure tax of US$ 25.00 is required to exit Peru.

Currency
The national currency is the Nuevo Sol and its abbreviation is the S/. sign.
It is recommended to carry US dollars while in Peru. Check current rates 
at www.oanda.com.                                                                      

US$ may be exchanged by Soles at any "cambista" (money changer) identified with a photo id. You will find several money exchange offices around the main plaza in Cuzco. Be prepare to pay up to 10% commission for Travelers Checks. Your best choice is to carry an ATM card and withdraw money as needed.

Transfer of Funds
Western Union Tel: 1-800-235-0000 (www.westernunion.com)

A person who wants to wire funds from the USA has to call or go to the nearest Western Union office. Transfer of funds could be done by phone with a Visa card. The sender should mention the country and the city where the money has to be transferred.

The receiver in Peru should phone 0-800-1-2080 to obtain the address of the Western Union office where the money will be sent. The receiver will have to present a valid ID and the Western Union transfer number provided by the sender. Payment of transfer will take place within 20 minutes after the transfer has been done in the US.

Following an assault, aggression, robbery
In Peru you can file a police report in any Police Station (Delegación Policial), but the Tourist Police is specialized in foreigners and will provide translation services at the time of filing a report.

The Tourist Police is located at:

Medical Care and Medical Travel Insurance
Your US medical insurance might not cover you during your stay in Peru. The cost of private physicians and clinics are higher than in the US and the clinics will request a guarantee of payment before you be attended. Therefore, you will not be released until the bill has been fully settled. Clinics in Lima are equipped to cope with serious emergencies.
Direccion General de Migraciones
Av. España, cdra. 7
Lima
Tel: 330-4020
Useful Telephone Numbers
Airlines:
American Airlines 211-7000
Lan Peru 215-1818
Delta Airlines 211-9211
Continental Airlines 221-6987
Aerocontinente 242-4260
Lloyd Aero Boliviano 241-5210
Lan Chile 241-5522