irrigation help please

My mother has a new house and we are planning on planting a shade garden among her cedar trees. Nothing has been planted there other than grass and we are planning on adding peat moss and composted manure to ammend the soil there. I thought since we were just getting started with this project I could get some helpful imput on what types or irrigation systems would work well there. We are planning on planting Rhodos, Hydrangeas, bleeding hearts, astilbe, hostas. I had thought about a soaker hose, but I am not skilled in this area at all. HELp!! Thanks again!