Pictures Of Sailboats Tips On Hanging Pictures And Small Shelves In PLASTER Walls?

Tips on hanging pictures and small shelves in PLASTER walls? - pictures of sailboats

We have an old house (1940), which has plastered walls origin. We would love to hang some pictures and shelves with little adornment Nick, a model sailboat, etc., are reluctant to do so, because I do not want to break the damaged plaster walls, fill a gap never Growning and a shelf or a framework that is not safe on the wall. All suggestions from others in similar situations related?
THANK YOU!