Bartending/Alcohol/Serving alcohol responsibly
Effects of alcohol on the body 
Alcohol is a very potent and potentially dangerous drug. It affects many systems of the body, especially the nervous and excretory systems. These effects can be dangerous if alcohol is used in excess. However, there are a number of benefits to alcohol, so it is important to understand its effects before consumption. Refer to the wikipedia article for additional information but ultimately consult your doctor on health issues.
Positive Effects 
Beers and wines have beneficial antioxidants in them. Non-alcoholic beers have become ever increasing in popularity, partially due to the fact that these benefits can be received without the effects of alcohol. Many people also find that alcohol and drinking are ways to relax and to socialize. These positive effects can easily be outweighed by excessive drinking, so it is important to remember moderation.
Negative Effects 
Alcohol has a profound effect on the nervous system, and intoxication can result in severe degradation of one's ability to make sound decisions. Effects of these bad judgments can range anywhere from self injury to death of one's self and others. It is important to understand the dangers of alcohol, and of drinking in general. Beyond the short term effects of intoxication, there are dangers in general with drinking over long periods of time in excess. Prolonged drinking can lead to obesity, alcoholism, liver and kidney damage, brain damage, circulatory and heart problems, and many other dangers. Those who have allergies to alcohol face dangers vastly magnified in comparison to others and must regulate their alcohol intake accordingly.
In addition to alcohol, there are dangers with specific drinks and the way that they are prepared. Flaming cocktails can cause damage to those who attempt to ingest them, and can lead to fires that may harm others and property. Other dangers include broken glass from glasses or bottles, as well as other dangers not listed. It is important that one remains coherent enough to understand these dangers, as a lack of cognizance can only magnify these problems.
Safe Usage 
By drinking responsibly, alcohol can be served, enjoyed, and used safely. It is important to remain aware of one's alcohol tolerance, and to know when to move to non-alcoholic beverages. As well as knowing one's own tolerances, it is important to keep a designated driver. Driving after consuming alcohol is under no circumstances safe, even if one is under the legal limit for intoxication.
Discontinuing service 
At the end of the night, it is important that bartenders stop selling alcohol before the time designated by the licence e.g. 3am. This of course depends on the bar's individual licence and/or special circumstances e.g. a festival. For example during the Edinburgh International Festival, Bars, Pubs and Clubs can have extended licences. Also it may also be necessary to discontinue service due to an accident or other unforeseen circumstance. There patrons must be politely informed of these circumstances as much as is in the interest of the company.
Serving a person already under the influence 
When bartending, precaution must be taken when serving customers that are already intoxicated or who are possibly below the age of consent. Each bartender must decide whether serving the customer more, or in fact any alcohol is responsible and legal.