Hi Mark, Justin is THE MAN!!!!!
Here's a wee trick I do to try to figure out strum patterns....
First of all.... put down your guitar..... yes.... put it down..... away.....step away from the guitar.
Now play the song on your cd player or mp3 player or whatever and listen to it. As you're listening concentrate on the beat of the song. Really get into the rhythm and now play a bit of air drums. Really get into it. Notice which hand is doing what, and on what beat. Now put the hand you DON'T strum with behind your back, or sit on it, just get it out of the way and concentrate on yout strumming hand. Listen to the song again, really getting into the rhythm. Now air drums but with only ONE hand on the side of your thigh or knee or something. The result should be some kind of up and down beat with your hand across your thigh or whatever. Transfer this to up-strums and down-strums and you should have a basic strum pattern. It may take a while to get into it and it may not be perfect but it helps me pick out a basic pattern.
Jeez, I hope you can follow that. Welcome aboard.