Bash scripting

Can anyone tell me how, in a bash script, I can move the contents of

variable $2 to variable $1 and so on?  I'm writing a bash script to
update some stuff but I'd like to be able to type 
script.sh noblah noit nothat
but everything is defaulted yes.
Currently., my script is something like
case "$1" in
    noblah)
        echo Not doing blah.
        $1="$2"
    ;;
    *)
        echo Doing blah;
    ;;
esac
case "$1" in
    nothis)
        echo Not doing this.
        $1="$2"
    ;;
    *)
        echo Doing this
    ;;
esac

That sort of thing. Can anyone help? Perhaps a nice online reference?
No books though, I don't have the money or time to buy one.

Thanks,
--
Bryce Chidester
Network Administrator
CoBryce Communications
Bryce AT BryceCo DOT Net
http://www.bryceco.net