how do you delete things off dashboard?

Launch Dashboard. Click on the "+" sign in he lower left corner.

Click on the little "X" that appears at the top-left of the widget you want to remove. Click on the big "X" now in the lower left corner of the screen to close the widget editor.

Its the " - " sign at the bottom left of the screen that will give the widgets the little "x" on the box.

It could be the x or the + or minus - it depends on the OS version. In my recollection: Mountain Lion have the + and -. Lion just has a +. Snow Leopard just has the x.