I want for example cut the letter A, if i do that now, it cuts it contours but also the inside of the A, so you can't really see that's its an A. how do i get the inside of the A, the triangle, to stay within the A, can this done by a simple line from outside the A to outside the A? Can anyone help me on this?

First of all... it should be a single path. If it's two paths, select both then path->combine (Ctrl+K).

If it still isn't cut out go to the fill and stroke dialog and change the fill rule to "evenodd" (on the fill tab... second button from the right).