From Route 50 West take Exit 39b Castle Marina, at the roundabout take the first right, pass the fire station and make a right on Postal Road. Rainbow Plaza will be on the right hand side.
From Annapolis:
Take route 50 to Exit 39A, then immediately turn left onto Postal Road. Rainbow Plaza will shortly be on your left.
.....If you miss Exit 39a,
take exit 39b, make a right at the light (18 Main St) and a left before the overpass. Rainbow Plaza will be on the right after the Post Office.