first of all rhino is awesome for architectural work. there are two methods i use to get sections out of rhino the first is the section command which will cut through your selected objects and create a set of curves which can then be exported to an illustrator file or dwg. the other is the cutplane command which is a little more tricky but whats nice about it is it shows everything behind the cut. just make the cut and split the objects then use the print command or the make2d command to get the view into a workable form.
hope this helps,