When planting a landscape, you will be disturbing the soil. Depending upon the slope, you may need to use a landscape fabric to keep the soil or mulch in place. Mulch to keep soil moisture in and protect the base of the shrub. Do not apply fertilizer at the time of planting. If you plant in the spring or summer, your plants will need to be watered twice a week through the first growing season, and maybe more often during dry, hot spells.
Early morning is the best time to water.
Weed, especially during the first year when your planting is just getting established and less able to tolerate competition. Mulching and weeding when the weeds are still small will make the job easier. It is also easier to pull out those unwanted green things when the ground is moist.