We discuss how and when we're going to take over the world with secret plots.
No, seriously, everybody does something to help out, everybody has a calling to participate teaching classes or doing other things to be involved.
When somebody is called they are called by the Bishop and their name is put before the group to indicate that they have an assignment within that group. Suppose you knew of something that would seriously compromise the ability of said individual to complete his task - for example a man who would be teaching lessons to youth was seen drinking recently - you then have the opportunity to bring that knowledge to your leaders (while you can do it publicly in the rare cases that this is done it's done privately).
Since normally there are no issues with worthiness it's your chance to raise your arm in support of that person, agreeing to help them out and support and sustain them as you can.
So we're really not "voting" we're agreeing to sustain the person and on extremely rare cases (I've seen this once in 33 years and it wasn't done with good intentions) we are privately raising awareness of why we couldn't sustain that person.
Everybody in attendance may choose to sustain the person; this includes all women and little children (who often raise their hands too late which is kind of cute).
That's what is generally meant with "church business" - it's internal organizational structure.
EDIT - it would be nice for wellington to answer the question rather than jump onto the same bandwagon he loves telling us about how much money is spent versus how much comes in while reminding us that nobody knows the numbers - except perhaps him because he's somehow quoting these numbers that he makes a big deal about nobody knowing.
I know enough to know that his estimations and simplification are completely wrong.