Beer-serving etiquette is susceptive to what part of the world you are in, what type of establishment you are in, and what type of beer you are drinking. There are very few hard and fast rules. That being said, there are a number of key things to remember.
No matter where you are serving a beer, if the beer comes in a bottle, you must offer a glass with it. Not all people, in all places, will use the glass, but it is mandatory that it is offered. In some cultures such as Japan, it is also obligatory that you pour the beer in front of the person. Even though in most other countries it is not considered necessary to pour the beer for the person, it is considered very good etiquette to at least offer to do so.
When pouring an ale or pilsner beer, it is considered good propriety to tilt the glass. The tilting of the glass stops the beer coming out all head and no body. The head is the foam that forms at the top of the glass once a beer is poured. However, you don’t want to end up with all body and no head on the beer either. The way to measure out the size of the head is directly related to how much you tilt the glass, and the speed in which you pour the beer. The more you tilt the glass, and the slower you pour, the less head you will have. As to how much head you provide to the beer is very reliant on where you are in the world. In Australia and New Zealand for example, it is etiquette to pour the beer with the least amount of head possible (less than a fingernail in size preferably). A sizeable head on a poured beer in either of these countries is considered deceitful and the person will feel as though you are cheating them. In Japan and most of Europe, on the other hand, the opposite is the case. You need a significant size of head on the beer as the size and white creaminess of the head directly correlates with the considered quality of the beer. In Europe, they have a mark on most glasses that indicate a litre. It is etiquette to pour the beer to this mark and the head should fill up the remainder of the glass from this point. The UK has adopted a similar practice with their pint glass.
With stout and wheat beers, it is a slightly different method of pouring altogether. With stout, especially the darkest and thickest of them such as Guinness, it is important to pour this kind of beer about half full in the glass and then to leave it to settle for at least a minute or two before pouring the remainder of the beer. This stops the beer from having too much head. With wheat beer, you have two ways of pouring it. The easiest method, and best way for beginners, is to place the glass upside down over the bottle. Then upturn the bottle and as the beer pours out into the glass, slowly remove the bottle until all contents is completely transferred. The second method is to pour the beer on a 45 degree angle, making certain there is no noise coming from the bottle as you pour. You completely pour the bottle out except for the last approximately 1/8th of beer. You need to let the remainder of the beer sit, then twirl it about to get as much of the sediment to mix in with the remainder of the liquid, and then pour it into the glass.
In terms of the temperature to serve beer and the types of glass and how you prepare the glass, it is very regional and very establishment orientated. In Japan, for example, you can get your glass frosted and direct from the freezer. They drink their beer very cold in this nation. In the Czech Republic their beer comes off tap in any number of degrees which affects the temperature and strength of the beer. In Ireland the Guinness is more often than not served at room temperature, but in recent years there is also a chilled version of the product that has become popular. In Belgium you must always rinse the glass first before you pour any beer into it. So there are no hard and fast rules in these instances, and it is best to follow the local custom rather than any determined universal method of etiquette.
1. A beginner's guide to Irish pub etiquette – IrishCentral.com
2. A Newbie's Guide to the Bar | Ethos magazine