Thank you, Robert, for your question!
  A general guide to watering is the following:

• 1-2 weeks after planting, water daily.
• 3-12 weeks after planting, water every 2 to 3 days.
• After 12 weeks, water weekly until roots are established.  

How much to water your plants is referenced in this article based on the size of the trunk and/or using the original purchased container as a guide. Check how moist your soil is by using something, a screwdriver or trowel, to dig down 6 inched to check your soil moisture. 
Watering newly planted trees and shrubs | UMN Extension

Be careful not to overwater.  Water should soak in quickly; your plants should never sit in a puddle of water for an extended period of time. This can lead to root damage. What you are aiming for is to get the roots established in the ground and this takes time. Mulching around your planting will help the soil retain moisture. When mulching the mulch should not come in contact with the base of the shrub.
   I have included two articles for further reading:
  The do’s and don’ts of irrigating landscape plants - MSU Extension

Watering Trees and Shrubs | University of Maryland Extension