Social greetings can be hard enough to navigate when in a different country (do you shake hands, hug, bow... ) but when social kissing gets thrown into the mix (especially when kissing is not the norm where you come from) things can get VERY confusing.

When do you kiss?

How many kisses?

Left cheek? Right cheek? Both? Ahhhh!!!!

(You can see why social kissing can lead to serious social anxiety.)

Oh, and to make matters worse, not only are there different rules in every country, there are different rules in every city in every country... sigh...

Feeling overwhelmed? Here are a few simple, general rules to help you out:

Don't kiss people you don't know unless you are introduced to them in a social environment.
It is usually right cheek first, but be prepared to change direction at the last minute. (NOTE: A sense of humor is useful for an accidental meet-in-the-middle moment)
Sound effects, air kissing, and leaving behind saliva are to be avoided AT ALL COSTS!
Don't linger and keep your hands WELL above the waist.
When in doubt, let the other person take the lead.

Cheek kissing is very common in most of Europe, the Mediterranean, Latin America, the Middle East, Quebec (in Canada), and in parts of the US. Here are a few places you will encounter this custom:

UNITED KINGDOM: Cheek kissing is not very common, outside of close family and friends, except for amongst the upper and middle classes (usually in London) and is historically considered to be a French practice.
FRANCE: The French seem to enjoy two kisses — once on each cheek called faire la bise — starting on the left, though a popular French joke states that you may recognize the city you are in by counting the number of cheek kisses as it varies widely across the country.
SPAIN: Spaniards like the two-kiss rule, often starting with the right cheek.
NETHERLANDS, BELGIUM, AND SWITZERLAND: Cheek kissing is a common greeting between relatives and friends. Usually, three kisses are exchanged.
MIDDLE EAST: Cheek kissing in the Arab world is common between friends and relatives. However, cheek kissing between a male and female is usually considered inappropriate, unless they are related or married. Cheek kissing in Turkey is also widely accepted.
PHILIPPINES: Cheek kissing or beso is a common greeting. But, it is important to note that the Philippine cheek kiss is a cheek-to-cheek kiss, NOT a lips-to-cheek kiss.
LATIN AMERICA: In this part of the world, cheek kissing is a universal form of greeting between a man and a woman or two women. It is not necessary to know a person well or be intimate with them to kiss them on the cheek.
QUEBEC (CANADA): In Quebec, cheek kissing is referred to as un bec. People of the opposite sex often kiss once on each cheek. Cheek kissing between women is common, but not between men.
NORTH AMERICA: Cheek kissing is common in large cities with a European flare, in the southern United States, and among immigrant groups that have carried their customs over from their native countries. This type of greeting is, almost exclusively, performed only among friends and family.