Very good tutorial, good job !
I already know a load of actionScript (i think i'm intermidate now), but for novices it's great ! I liked the yellow markings on the script, more ppl should use it...
Your animations aren't too good, but hey, i suck at drawing, and ur explaining how to make a game, so that's not a problem at all.
In the future, include a previous button as well, for when you've missed something.
And for the crosshair, you should also make the mouse itsself invisible,
i think it was mouse.hide();
Don't mind that one jerk, you did a great job !
Now look at yourself and be proud ~_^