Totally free 'Wonder' by R.J. Palacio resources
Wonder is such a wonderful book - sorry! If you are thinking of using it in class any time soon - you'll need to know what resources are out there - and TBH there's quite a lot - making this an excellent choice.
This 36-page PDF from Penguin Books UK includes lesson plans, reading activities and other resources.
This American website includes a fantastic range of teaching resources. You will be really impressed with what is on offer here.
Both the these are official websites, but a simple search will help you find lots of other fantastic free resources.