What is a swim Meet anyway?
Every swim meet starts with a warm up, with swimmers swimming several laps to get loosened up, get a feel for the water and honestly to wake up. 
Following the warm up, there is some wait time.  There are things that must take place prior to the start of the meet. 
Once the meet is underway, events 1-78 are swum in order.  Odd numbered events are boys events and even numbered events are girls events.
Each swimmer may swim a maximum of 2 relay's and 3 individual events, but may swim as little as 1 event.
The order of the events is by stroke, not by age.  Meaning for example events 18-28 are the freestyle events, swimmers of each age will swim that event before the meet moves on to the next event.  Because of this, swim meets are a 4 hour commitment.  Here is how your event schedule may look if your child is an 8 year old girl:  she may swim events 8,20,30,50,and 70.  So please come to each meet prepared to stay the entire time. 
During the meet you will be asked to help in different ways.  Timers are the most need positions, and honestly the best because that puts you right at pool side where all the action is.  We time 2 shifts, so you don't have to stand there the entire 4 hours and shade is provided.
Other places you might be asked to help are:
at the concession stand
verifying times after they've been entered into the computer
running water to the timers
"tearing down" at the end of the meet
And that about covers it.  I hope this was helpful.  I know it is a little intimidating at first, but it really is a lot of fun!