Customs in Qatar

For all participants who will be traveling to Doha, here are some cultural customs and guidelines to keep in mind (as sourced from the official Qatar Tourism Authority website):

Clothing
Men and women should dress modestly as a courtesy to both Qataris and Muslims. Swimsuits and beachwear is acceptable at the hotel beaches (don’t forget sunscreen), but it is not appropriate to expose the body in other public areas. Topless sunbathing is definitely taboo. Tops should cover the shoulders and upper arms, and skirts or shorts should fall to or below the knee. Women are not obliged to cover their hair. Visitors should be thoughtful of their clothing particularly in the Holy Month of Ramadan, or when in public areas.
The extreme heat and high humidity of summertime means lightweight fibres are advisable (clothes made from ‘wicking’ – high-tech polyester – material are invaluable); covering up susceptible parts of your body whilst outside they will also prevent sunburn. However a jumper or wrap may be needed inside malls, cinemas and restaurants, as the air conditioning can be fierce. Wintertime can be chilly, especially in the evenings, and there is also a chance of rain, so coats and closed shoes will be useful.
Alcohol
Qatar has a relatively liberal attitude to the consumption of alcohol by non-Muslims, and liquor is available in most hotels (in rooms, restaurants and bars). However, it is strictly forbidden to bring any alcohol into the country, including duty free, and the sale of alcohol is prohibited in Ramadan in all hotels. There are stiff penalties for consuming alcohol other than on licensed premises or in homes covered by liquor permit. Drunk-driving is a serious offence in Qatar and will not be tolerated.
The effects of alcohol can be exacerbated by the heat and humidity of the local climate. To avoid dehydration, be sure to drink plenty of water, especially in the hotter summer months.
Language
Arabic is the official and main language, but English is widely spoken in every part of the country.
Despite the fact that most Qatari people speak fluently English, they feel honored to see their guests speaking a few words in Arabic:
Hello (welcome) – marhaba
Hello (peace be upon you) – assalamo alaykum
Good morning – sabah al khair
Good afternoon/evening – misaa al khair
Goodbye – ma’salaama
How are you? – kaif halaak (m) / kaif haalik (f )
Please – min fadlak
Thank you – shukran
Not at all – afwan
Yes – na’am
No – la
I want a taxi – ureed taxi
Right – yameen
Left – yasar
Straight ahead – alatool
Let’s go – yalla
Finished – khallas
No problem – ma fi mushkila
This/that – hatha / hathaak
I want to buy…/I’d like – areed ashtiri…/ ana areed
The bill please - fatoura, laow samaht
Yesterday/today/ tomorrow – ams / alayum/bukra
God willing – insha’Allah
Visa requirements 
A simple 30-day visa covering both business and leisure travel is available to passport holders from 33 countries*, including the UK and Ireland, most of continental Europe, the USA and Canada, Australia and New Zealand, and selected Asian nations.
Visas cost QR 105 (2009) and are conveniently issued upon arrival at Doha International Airport.
Many visas can now be processed online at the Ministry of Interior’s website (www.moi.gov.qa). The Ministry will only accept credit cards as payment.
*Visas on Arrival
Andorra; Australia; Austria; Belgium; Brunei; Canada; Denmark; Finland; France; Germany; Greece; Hong Kong; Iceland; Ireland; Italy; Japan; Liechtenstein; Luxembourg; Malaysia; Monaco; Netherlands; New Zealand; Norway; Portugal; San Marino; Singapore; South Korea; Spain; Sweden; Switzerland; UK (with the right of abode); USA; Vatican City
Climate
Qatar benefits from a year-round sunshine, with temperatures ranging from 25ºC (74ºF) up to 45ºC (113ºF) in summer. The best months to enjoy Qatar pleasant weather are from October to May. The climate of Qatar is typical of hot and arid desert lands, pleasant in winter and extremely hot in summer. Short transitional periods separate the two main seasons.
Voltage
Electricity is 220-240v with a frequency of 50 Hertz.
British standard plugs are utilized.
Water
Tap water is generally safe to drink in major cities, but water quality is variable in rural areas.
If in doubt, do not drink tap water unless it has been boiled, filtered or chemically disinfected.