The recommended images for School Zone are

Logo
Width:221px
Height:25px

Banner image
Width:1920px
Height:692px

Featured Courses
Width:276px
Height:276px

Information section : 
Width:63px
Height:37px

Testimonials ( Homepage) 
Width: 125px
Height: 125px;

Why Choose us Section ( Homepage) 
Width52px
Height:56px

Blog  Section ( Homepage)
Width:848px
Height:480px

Blog featured (Sidebar)
Width:750px
Height:458px

Post Featured Image(Full width)
Width:1140px
Height:695px