A common example of an idiom is "to kick the bucket," which is normally understood to relate to the process of dying. A well-used idiom referring to heavy rainfall is "raining cats and dogs."
Some idioms refer to people or actions; examples of these include "rub someone the wrong way," meaning to annoy or bother somebody, and "jump the gun," meaning to do something unexpectedly early. There are many idioms relating to color, such as "once in a blue moon," referring to something that happens rarely. Different languages use different idioms to express the same idea; for example, in Norwegian and Czech, "walking around the porridge" equates to "beating around the bush," which is an English idiom meaning not getting to the point. IdiomSite.com gives many more examples of common idioms and their meanings.