When you go to create an object, click the object you want to create from the menu (box, sphere, etc) and check Autogrid on just above the object names. You will be able to draw your object on the face normal of another object.
As japetus said autogrid is an option. In that way you will create an object on to the normal of any face of any object. The problem with this is that the new object will be positioned according to the normal of that given face and it might get difficult to edit later on. What you can do is create the object you want, edit it and then use "normal align". In that way you can align two objects according to two faces you select, similar to an autogrid. The normal align icon is in the align rollout.
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You can copy your object, use the cut tool to cut out the panel shape you want, delete the rest, and extrude that piece.
I made this tutorial a while ago that might help you, if you can put up with my accent :shiner:
3ds Perfect Paneling on Vimeo
thanks i know i didnt ask for it but stil glad iv found it