Sometimes an argument will not follow the order described above. For instance, the conclusions might be stated first, and the premises stated afterwards in support of the conclusion. This is perfectly valid, if sometimes a little confusing.
Arguments are harder to recognize than premises or conclusions. Many people shower their writing with assertions without ever producing anything which one might reasonably describe as an argument. Some statements look like arguments, but are not.

For example:

"If the Bible is accurate, Jesus must either have been insane, an evil liar, or the Son of God."
The above is not an argument, it is a conditional statement. It does not assert the premises which are necessary to support what appears to be its conclusion. (Even if we add the assertions, it still suffers from a number of other logical flaws -- see the section on this argument in "Alt.Atheism Frequently Asked Questions".)
Another example:

"God created you; therefore do your duty to God."
The phrase "do your duty to God" is neither true nor false. Therefore it is not a proposition, and the sentence is not an argument.
Causality is important. Suppose we are trying to argue that there is something wrong with the engine of a car. Consider two statements of the form "A because B". The first statement:

"My car will not start because there is something wrong with the engine."
The statement is not an argument for there being something wrong with the engine; it is an explanation of why the car will not start. We are explaining A, using B as the explanation. We cannot argue from A to B using a statement of the form "A because B".
However, we can argue from B to A using such a statement. Consider:

"There must be something wrong with the engine of my car, because it will not start