Konstrukor,
The way to solve that problem is to first put a custom property to your subassemblies (Using say "description" under the Property name in File, Properties). And type in the information that you want in this description field. Then place a note the drawing, making sure that you put the note inside the view border). A dialog box appears, use "Model in view to which the annotation is attached", then under the pull the down you will find "Description". Select it and it should show what you have entered in the subassembly.
Hopefully this is clear and it will work.