Visa and Permit
All foreign travelers(except Indian nationals) require a visa to travel to Nepal. You can obtain it in advance from Nepalese Embassies & Nepalese Consulates abroad. You can also get an on-arrival visa upon arrival at the airport or any port of entry. Some rural and restricted areas require a special permit. Popular trekking regions like the Annapurna, Langtang Valley, and the Everest region do not require special permits, but you have to pay the National Park fee. Whereas restricted areas like the Mustang region, Manaslu region, Tsum Valley, Narphu Valley, and the Dolpo region require restricted area permit. These permits range from US$10-500 per week. Besides restricted area permit is issued only to a group of at least two members through registered travel operators. The permit is valid for the specific route, and no other than the indicated shall be permitted to be visited

Medical advice
Travelers should bring their own prescribed medicine. Common medicines are easily available but still may bring your own. Some medicines are usually not available in remote areas. So bring the necessary medicines along with you. It is highly advised to get an injection against typhoid, meningitis, and hepatitis before getting into Nepal. Malaria is not a problem in the higher area of Nepal but can be found at the lower altitudes. Please consult your doctor for more information.
Altitude problem: Often known as acute mountain sickness, is particularly a matter of important medical consideration while trekking the Himalayas. Altitude sickness means the effect of altitude on those who ascend too rapidly to elevations above 3000 meters. Symptoms like headache, nausea, shortness of breath, fatigue, etc. can be encountered as initials of the sickness. The major information source on prevention and treatment of the sickness can be obtained from the following links or consult your doctor.
Visit this site for helpful Medical advice in visiting Nepal http://www.ciwec-clinic.com/

When to Go?
The best time to visit Nepal is the Spring and the Fall. Late February to May is the end of the dry season and is the best season to travel in Nepal. Visibility is not that good but the weather is warm, and many of wildflowers are in bloom. During October-November, the weather is balmy, the air is clean, visibility is perfect, and the country is lush following the monsoon. This is the best season for trekking and mountain expeditions. In December and January, the climate and visibility are good but it can be chilly and discourage from trekking. The rest of the year is fairly unpleasant for traveling: June and early September are generally too hot and dusty for comfort, and the monsoon from mid-June to September obscures the mountains in clouds and turns the trails and roads to mud.

Getting around
Several airlines offer domestic air services to different parts of Nepal. But flights are relatively expensive compared to Public buses. There are public bus services connecting different cities, but they are uncomfortable and time-consuming. However, there are luxury tourist coach services to some cities mainly Kathmandu Chitwan and Pokhara, and vice versa. These are aimed specifically at tourists, which has acceptable comfort & timely service. There are no trains and no drive-yourself rental cars in Nepal. Cars with drivers can be hired. Local transport in the Kathmandu Valley and around Pokhara includes taxis, buses, micro buses, tempos (three-wheelers), bicycle rickshaws, and bicycles.

Currency & Exchange
The currency of Nepal is called the Nepalese Rupees. The foreign currency exchange rates are set by the Central Bank of Nepal. There are several government-registered money exchange counters, where you can change your money to local currency.
Major International currencies such as the US dollar, pounds sterling, Euro, Swiss Frank, Australian dollar are readily accepted. If you’re trekking, take enough small-denomination cash in local currency with you to last the whole trek.
Exchange Rate by Nepal Rastra Bank:https://www.nrb.org.np/

Book & Readings:
There are plenty of books to read in Nepal. For the recommended list click here.

Tipping
Tipping is becoming fairly common in upmarket restaurants in Nepal, so leave around 10% of the bill if service was good. There’s no need to tip in cheaper establishments or taxi drivers. Guides and Porters on treks, however, should be tipped around 10-15 dollars per day. Bargaining is commonplace in markets and tourist shops, but treat it as a form of polite social discourse rather than a matter of life and death.

Visiting a Temple
Always walk clockwise around Buddhist stupas, chortens, and mani walls. Remove your shoes before entering a Buddhist or Hindu temple or sanctuary. You may also have to remove any items made from leather, such as belts and bags. Most of the Hindu temples do not permit westerner to enter.
It’s the custom to give a white scarf or Khada to a Buddhist abbot when you are introduced. The honorific title Rimpoche is usually bestowed on abbots. The scarves can easily be found at Tibetan shops.

Visiting a Nepali Home
In a Nepali home, the kitchen is off-limits to guests. Avoid polluting food by inadvertently touching it or bringing it into contact with a used plate or utensil. Using a fork or spoon to serve out more food will do this. Putting your used plate on a buffet table risks making the food still on table polluted. Notice how Nepalese drink from a cup or water vessel without letting it touch their lips.

Photography
Do not intrude with a camera, unless it is OK with the people you are photographing. Ask before a temple or a monastery compound whether it is permissible to enter and take photographs.

Language
It’s quite easy to get by with English in Nepal; with those, you have to deal with in Kathmandu & Pokhara valley. Along the main trekking trails, particularly the Annapurna Circuit, and the Everest region, English is widely understood. However, Nepali on the other hand is a fairly easy language and useful to come in contact with the locals. Nepali is closely related to Hindi and, like Hindi, is a member of the Indo-European group of languages.

Although Nepali is the national language of Nepal and is the linking language between all the country’s ethnic groups there are many other languages spoken. The Newars of the Kathmandu Valley, for example, speak Newari, and there are other languages spoken by the Tamangs, Sherpas, Rais, Limbus, Magars, Gurungs, and other groups. In the Terai, bordering India, Hindi, and Maithali, another Indian language of their region, are often spoken. The magic word Namaste -translated it means I salute the god in you, but it is used as an everyday greeting encompassing everything from Hello to How are you? and even ‘see you again soon. Properly used it should be accompanied with the hands held in a prayer-like position, the Nepali gesture equivalent to westerners shaking hands.